Perry L. McCarty
Affiliate, Stanford Woods Institute for the Environment
Bio
Perry L. McCarty, Silas H. Palmer Professor Emeritus, came to Stanford University in 1962 to found a new multidisciplinary education and research program in environmental engineering and science that became a model for others throughout the country. From 1980 to 1985 he was Chairman of Stanford's Department of Civil and Environmental Engineering, and from 1989 to 2002 he served as Director of the Western Region Hazardous Substance Research Center. He received a B.S. Degree in civil engineering from Wayne State University (1953), and M.S. (1957) and Sc.D. (1959) degrees in sanitary engineering from M.I.T.
The focus of McCarty's research, teaching, and writing has been on water, with a primary interest in biological processes for the control of environmental contamination. His early research was on anaerobic treatment processes, biological processes for nitrogen removal and water reuse. Recent interests are on aerobic and anaerobic processes for the treatment of domestic and industrial wastewaters, and the movement, fate, and control of groundwater contaminants.
His numerous awards and accolades for pioneering work on improving water quality worldwide includes memberships in the American Academy of Arts and Sciences and the National Academy of Engineering. McCarty won the Tyler Prize for Environmental Achievement in 1992, the Athalie Richardson Irvine Clarke Prize for Outstanding Achievements in Water Science and Technology in 1997, and the Stockholm Water Prize in 2007. In 2011 the Association of Environmental Engineering and Science Professors Foundation established the Perry L. McCarty AEESP Founder's Award, given annually in recognition of McCarty's significant contributions to environmental engineering education, research, and practice. The Directorship of the Stanford Woods Institute for the Environment, part of the Stanford Doerr School of Sustainability, was named in his honor.
McCarty has written and coauthored over 350 papers, plus the textbooks, Chemistry for Environmental Engineering and Science, and Environmental Biotechnology - Principles and Applications.
Administrative Appointments
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Professor, World Class University Program, Department of Environmental Engineering, Inha University, Incheon, South Korea (2008 - 2013)
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Chair Professor, Department of Environmental Science and Engineering, Tsinghua University, Beijing, China (2004 - 2007)
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Lecturer, Stanford Canada and Great Lakes College (2003 - 2003)
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Silas H. Palmer Professor of Civil Engineering Emeritus, Stanford University (1999 - Present)
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Director, Western Region Hazardous Substance Research Center, Stanford University (1989 - 2003)
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Chairman, Department of Civil Engineering, Stanford University (1980 - 1985)
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Silas H. Palmer Professor of Civil Engineering, Stanford University (1975 - 1999)
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Visiting Professor, University of Cape Town, South Africa (1971 - 1971)
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Visiting Lecturer, Summer Institute in Advanced Sanitary Chemistry, Harvard University (1969 - 1969)
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Faculty Member, Curso de Postgrado en Ingenieria Hidrologica, Ministerio de Obros Publicos, Venezuela (1968 - 1972)
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Honorary Research Associate, Harvard University (1968 - 1969)
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Professor of Civil Engineering, Stanford University (1967 - 1975)
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Associate Professor of Civil Engineering, Stanford University (1962 - 1967)
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Assistant Professor of Sanitary Engineering, Massachusetts Institute of Technology (1959 - 1962)
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Instructor of Sanitary Engineering, Massachusetts Institute of Technology (1958 - 1959)
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Instructor, Department of Civil Engineering, Wayne State University (1953 - 1954)
Honors & Awards
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Inductee, Engineering & Science Hall of Fame, Dayton, Ohio (2019)
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Stanford Engineering Hero, School of Engineering, Stanford University (2016)
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Gordon Maskew Fair Award, American Academy of Environmental Engineers and Scientists (2014)
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Joan Hodges Queneau Palladium Medal, National Audubon Society (2013)
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Distinguished Member, American Society of Civil Engineers (2012)
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Fellow, Water Environment Federation (2012)
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Honorary Fellow, The Chinese Institute of Environmental Engineering, Taiwan (2011)
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Honorary Professor, Harbin Institute of Technology, China (2011)
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Honorary Professor, National Chiao Tung University, Taiwan (2011)
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Honorary Degree of Doctor of Engineering, Nanyang Technological University, Singapore (2010)
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Honorary Member, American Academy of Environmental Engineers (2009)
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Water Industry Hall of Fame, American Water Works Association (2009)
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Lifetime Achievement Award, Brown and Caldwell (2008)
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Lifetime Achievement Award, Groundwater Resources Association of California (2008)
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Stockholm Water Prize, Stockholm International Water Institute (SIWI) (2007)
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Abel Wolman Distinguished Lecturer, National Academies (2001)
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The Athalie Richardson Irvine Clarke Prize, National Water Research Institute (1997)
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Fellow, American Academy of Arts and Sciences (1996)
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J. James R. Croes Medal, American Society of Civil Engineers (1995)
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Fellow, California Council on Science and Technology (1994)
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Fellow, American Academy of Microbiology (1993)
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Founder's Award, Association of Environmental Engineering Professors (1992)
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Honorary Degree of Doctor of Engineering, Colorado School of Mines (1992)
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Tyler Prize for Environmental Achievement, University of Southern California (1992)
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CH2M HILL Research Award, Association of Environmental Engineering Professors (1990, 1997)
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A. P. Black Research Award, American Water Works Association (1989)
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Honorary Member, Water Environment Federation (1989)
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Outstanding Publication Award, Association of Environmental Engineering Professors (1985, 1988, 1998, 2003)
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Distinguished Professor Lectureship, Association of Environmental Engineering Professors (1984)
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Thomas R. Camp Lecturer Award, Boston Society of Civil Engineers (1983)
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Honorary Member, American Water Works Association (1981)
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Fellow, American Association for the Advancement of Science (1980)
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Engineering-Science Research Award, Association of Environmental Engineering Professors (1979, 1983, 1992)
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Simon W. Freese Environmental Engineering Lecture Award, American Society of Civil Engineers (1979)
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Member, National Academy of Engineering (1977)
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Thomas Camp Award, Water Environment Federation, for Unique Application of Engineering Research (1975)
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Walter L. Huber Research Award, American Society of Civil Engineers, (1964)
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Harrison P. Eddy Award, Water Environment Federation for Noteworthy Research (1962, 1977)
Boards, Advisory Committees, Professional Organizations
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Chair, External Review Committee, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore (2016 - 2016)
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Member, Expert Panel on Development of Water Recycling Criteria for Potable Reuse, National Water Research Institute (2014 - 2016)
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Chair, External Review Committee, Academic Program Review, Environment Science and Engineering, Tsinghua University, China (2010 - 2010)
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Member, Environmental Science and Engineering Visiting Committee, Colorado School of Mines (2009 - 2009)
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Member, Peer Review Team, Capital Regional Districts Core Area Wastewater Management Program, Victoria, British Columbia (2009 - 2009)
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Lee Kuan Yew Water Prize Nominating Committee, Singapore Public Utility Board (2008 - 2021)
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Member, Project Evaluation Panel, Ministry of the Environment and Water Resources, Singapore (2006 - 2021)
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Associate-Editor-in-Chief, Frontiers of Environmental Science & Engineering, Tsinghua University, China (2006 - 2017)
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Member, External Advisory Committee, Water: Systems, Science, Society Program, Tufts University (2006 - 2013)
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Member, Committee on Sediments Dredging at Superfund Megasites, National Research Council (2006 - 2007)
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Member, Environmental Science & Engineering Visiting Committee, National University of Singapore (2006 - 2007)
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Member, Research Advisory Board, National Water Research Institute (2005 - 2010)
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Member, The Athalie Richardson Irvine Clarke Prize Executive Committe, National Water Research Institute (2005 - 2007)
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Member, Vietnam Education Foundation Review Panel, The National Academies (2005 - 2005)
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Member, Oversight Committee for Strengthening Science-Based Decision, The National Academies (2002 - 2007)
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Member, Committee on Water Quality Improvement for The Pittsburgh Region, National Research Council (2002 - 2004)
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Member, Civil Engineering Peer Committee, National Academy of Engineering (2001 - 2004)
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Member, Expert Panel on Water Reuse, West Basin Municipal Utility District, Los Angeles (2001 - 2002)
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Member, Tritium Migration Independent Scientific Peer Review Panel, U.S. Department of Energy (2001 - 2002)
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Member, Expert Panel for Review of Groundwater Treatment Technology, Aerojet General Corporation (2000 - 2001)
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Member, Chemical & Environmental Engineering Department Industrial Advisory Committee, University of Arizona (1999 - 2002)
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External Examiner, Department of Chemical and Environmental, National University of Singapore (1999 - 2001)
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Member, Committee on Assessment of Risks from Remediation of PCB-Contaminated Sediments, National Research Council (1999 - 2001)
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Chairman, Blue Ribbon Panel on San Diego Water Repurification Project, City of San Diego (1998 - 1998)
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Member, Panel on Groundwater Contamination, Scientific Committee on Problems of the Environment (1998 - 1995)
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Member, Science Advisory Board, U.S. DOD Strategic Environmental Research and Development Program (1997 - 2010)
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Member, Committee on Intrinsic Bioremediation, National Research Council (1997 - 2000)
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Member, Blasker Award Selection Committee, Blasker Award for Environmental Science and Engineering (1996 - 2001)
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Chairman, Virtual Commission on Environmental Management Science, National Research Council (1996 - 1998)
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Member, Selection Committee, Mitchell International Prize for Sustainable Development, National Academy of Sciences (1996 - 1997)
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Member, Visiting Committee, Dept. of Civil Engineering, Northwestern University (1996 - 1996)
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Member, Visiting Committee, Dept. of Civil Engineering, Cornell University (1996 - 1996)
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Member, National Forum on Science and Technology Goals - No. 1: Environment, National Research Council (1995 - 1995)
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Member, Commission on Geosciences, Environment, Resources, National Research Council (1994 - 1997)
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Associate Editor, Journal of Contaminant Hydrology (1993 - 2006)
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Environmental Technology Advisory Board, ALCOA (1993 - 2005)
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Member, Editorial Board, Biodegradation (1993 - 2000)
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Member, Advisory Board, Marine Bioremediation Program, University of Washington (1993 - 1996)
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Member, Visiting Committee, Dept. of Environmental Engineering and Science, University of North Carolina, Chapel Hill (1992 - 1992)
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Member, Visiting Committee, Environmental Engineering Program, University of Texas, San Antonio (1992 - 1992)
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Chairman, Committee on Remedial Action Priorities for Hazardous Waste, National Research Council (1991 - 1994)
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Chairman, Panel for review of proposals for Centers of Excellence, U. S. Environmental Protection Agency (1991 - 1991)
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Member, Evaluation Committee on Civil Engineering, Member, Evaluation Committee on Civil Engineering (1990 - 1990)
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Member, Board on Radioactive Waste Management, National Research Council (1989 - 1996)
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Member, Research Council, Water Environment Federation Research Foundation (1989 - 1995)
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Member, Civil Engineering Visiting Committee, Massachusetts Institute of Technology (1989 - 1993)
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Member, Advisory Committee for Center for Environmental Health Sciences, Massachusetts Institute of Technology (1989 - 1992)
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Chairman, Program Planning Committee, International Symposium on Processes Governing the Movement and Fate of Contaminants in Groundwater (1989 - 1989)
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Chairman, Panel for review of Hazardous Substance Research Center Proposals, U. S. Environmental Protection Agency (1988 - 1988)
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Member, Panel for review of Superfund Phase II proposals, National Institute of Environmental Health Sciences (1988 - 1988)
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Member, Visiting Committee, Department of Civil Engineering, University of Southern California (1987 - 1987)
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Member, Visiting Committee, Division of Engineering and Applied Science, California Institute of Technology (1986 - 1992)
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Member, Scientific Advisory Panel on Groundwater Recharge, State of California (1986 - 1987)
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Member, Technical Advisory Committee, Clean Sites, Inc (1985 - 1994)
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Member, Commission on Mathematics, Physics, Resources, National Research Council (1985 - 1988)
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Member, Visiting Committee, Dept. of Civil Engineering, Princeton University (1985 - 1988)
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Chairman, Visiting Committee, Dept. of Civil Engineering, University of Minnesota (1985 - 1985)
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Member, Drinking Water Standards Committee, American Water Works Association (1984 - 1996)
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Member, Engineering Education Board, National Academy of Engineering (1984 - 1987)
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Chairman, Panel on Energy, Environment, and Resources, National Research Council (1984 - 1986)
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Member, Committee on Groundwater Protection, National Research Council (1984 - 1986)
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Member, Engineering Research Board, National Research Council (1984 - 1986)
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Member, Task Force on Ground Water Pollution, Office of Technology, U.S. Congress (1983 - 1985)
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Chairman, Scientific Panel to Evaluate Sacramento-San Joaquin Delta Water Quality, California Department of Water Resources (1982 - 1983)
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Guest Lecturer, Chinese Academy of Sciences, Biogas Production, Guangzhou and Chengdu, China (1982 - 1982)
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Member, Advisory Subcommittee for Civil and Environmental Engineering, National Science Foundation (1981 - 1985)
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Trustee, American Water Works Research Foundation (1981 - 1985)
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Trustee, Research Division, American Water Works Association (1981 - 1985)
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Director, International Conference on Ground Water Quality (1981 - 1981)
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Chairman, Scientific Advisory Board, Southern California Coastal Water Research Project (1980 - 1986)
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Member, Scientific Advisory Board, National Center for Ground Water Research (1980 - 1986)
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Member, Visiting Committee, Division of Applied Science, Harvard University (1980 - 1985)
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Member, Wastewater Reclamation Health Effects Advisory Panel, California Department of Health Services (1980 - 1985)
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Chairman, Committee to Review Potomac Estuary Experimental Water Treatment Plant, National Research Council (1979 - 1984)
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Member, Committee to Review the Metropolitan Washington Area Water Supply Study, National Research Council (1979 - 1984)
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Member, Expert Committee on Engineering and Technology, International Joint Commission on the Great Lakes (1979 - 1982)
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Member, Panel on Wastewater Reuse Criteria, National Research Council (1979 - 1982)
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Member, Aquaculture Technical Advisory Committee, California Water Resources Control Board (1979 - 1981)
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Member, Innovative and Alternative Technology Committee, California Water Resources Control Board (1979 - 1981)
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Member, Scientific Advisory Board, Member, Scientific Advisory Board (1979 - 1980)
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Member, Technical Delegation to the People's Republic of China, Stanford University (1978 - 1978)
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Member, Commission on Natural Resources, National Research Council (1977 - 1980)
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Vice Chairman, Environmental Studies Board, National Research Council (1977 - 1980)
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Chairman, Camp Medal Award Committee, Water Pollution Control Federation (1977 - 1979)
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Chairman, Research Committee, Technical and Professional Council, American Water Works Association (1976 - 1981)
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Member, Environmental Studies Board, National Research Council (1976 - 1981)
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Member, Technical and Professional Council, American Water Works Association (1976 - 1981)
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Member, Potomac Estuary Committee, National Research Council (1976 - 1979)
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Chairman, Panel on Treatment Processes, National Research Council (1976 - 1977)
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Member, Engineering Board of Consultants, John Wiley & Sons (1974 - 1980)
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Member, T & P Research Committee, American Water Works Association (1973 - 1976)
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Member, Water Quality Policy Committee, National Research Council (1973 - 1976)
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Chairman, Water Quality Division, American Water Works Association (1972 - 1973)
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Participant, Study on the Effect of Rapid Urbanization on the Environment in Seoul, South Korea, Smithsonian Institution (1972 - 1972)
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Member, Sanitary Engineering Advisory Committee, California Department of Public Health (1971 - 1975)
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Member, Committee on Control of Nitrates, American Water Works Association (1971 - 1974)
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Member, Advisory Board, Environmental Science & Technology (1971 - 1973)
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Member, George Westinghouse Environmental Student Award Committee, American Society of Engineering Education (1971 - 1973)
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Member, Symbiotic Study on Agricultural Wastewaters, U.S. Bureau of Reclamation and California Department of Water Resource (1971 - 1973)
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Vice Chairman then Chairman, Environmental Sciences – Water Conference, Gordon Research Conference (1971 - 1972)
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Member, Workshop on "Water in Man's Life in India", U.S. National Academy of Science – Indian National Science Academy (1971 - 1971)
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Member, Training Grants Division, U.S. Environmental Protection Agency (1970 - 1975)
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Member, Committee on Quality Control in Reservoirs, American Water Works Association (1970 - 1972)
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Member, Committee on Wastewater Reclamation, American Water Works Association (1970 - 1972)
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Member, Board of Directors, Biostimulation and Biotoxicity Study, California Water Resources Control Board (1970 - 1971)
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Vice Chairman, Environmental Engineering Division, American Society of Engineering Education (1968 - 1969)
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Trustee, Water Quality Division, American Water Works Association (1967 - 1974)
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Chairman, National Symposium on Estuarine Pollution, American Society of Civil Engineers (1967 - 1967)
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Chairman, San Francisco Sanitary Engineering Section, American Society of Civil Engineers (1967 - 1967)
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Member, Interagency Agricultural Wastewater Treatment Study, Fed. Water Pollution Control Admin., U.S. Bureau of Reclam., Calif. Depart. of Water Resources (1966 - 1971)
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Chairman, Committee on Gases in Water, Standard Methods (1965 - 1970)
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Chairman, Task Group on Nutrients in Water, American Water Works Association (1965 - 1969)
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Assistant Editor, Sanitary Engineering Division Newsletter, American Society of Civil Engineers (1965 - 1968)
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Member, Sanitary Engineering Committee, American Society of Engineering Education (1965 - 1968)
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Member, Program Planning Committee, Water Pollution Control Federation (1964 - 1970)
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Member, Research Grants Study Section on Environmental Science and Engineering, U.S. Public Health Service (1964 - 1966)
Professional Education
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Sc.D., Massachusetts Institute of Technology, Sanitary Engineering (1959)
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S.M., Massachusetts Institute of Technology, Sanitary Engineering (1957)
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B.S., Wayne State University, Civil Engineering (1953)
Patents
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Bae, J. H., Kim, J. H., McCarty, P. L.. "Singapore Patent 2012064267 Fluidized Membrane Bioreactor", Inha University, Feb 4, 2015
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Spormann, A. M., Muller, J. A., Rosner, B. M., von Abendroth, G., Meshulam-Simon, G., and McCarty, P. L.. "United States Patent 8,647,824 Microbial Reductive Dehalogenation of Vinyl Chloride", Leland Stanford Junior University, Nov 11, 2014
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Bae, J. H., McCarty, P. L., Kim, J. H.. "South Korea Patent 10-1342678 Waste Water Treatment System Combining Two-Stage Anaerobic Reactor and Nitrogen Removal Process", Inha University, Dec 11, 2013
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Bae, J. H., Kim, J. H., McCarty, P. L. "United States Patent 8,404,111 Fluidized Membrane Bioreactor", Inha University, Mar 26, 2013
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Bae, J. H., Kim, J. H., McCarty, P. L.. "South Korea Patent 10-1157332 Fluidized Membrane Bioreactor", Inha University, Jun 6, 2012
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Spormann, A. M., Muller, J. A., Rosner, B. M., von Abendroth, G., Meshulam-Simon, G., McCarty, P. L.. "United States Patent 8,063,192 Microbial Reductive Dehalogenation of Vinyl Chloride", Leland Stanford Junior University, Nov 22, 2011
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McCarty, P. L., Bachmann, A.. "Japan Patent 1971981 Bioconversion Reactor", Leland Stanford Junior University, Sep 27, 1995
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Semprini, L., McCarty, P. L., Kitanidis, P. K., Bae, J.H.,. "United States Patent 5,302,286 Method and Apparatus for In Situ Groundwater Remediation", Leland Stanford Junior University, Apr 12, 1994
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McCarty, P. L., Alvarez-Cohen, L.. "United States Patent 5,139,682 Zeolite Enhanced Organic Biotransformation", Leland Stanford Junior University, Aug 18, 1992
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McCarty, P. L., Bachmann, A.. "United States Patent 0213691 European Patent Bioconversion Reactor", Leland Stanford Junior University, Jul 22, 1992
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McCarty, P. L. and Bachmann, A.. "United States Patent 5,091,315 Bioconversion Reactor", Leland Stanford Junior University, Feb 25, 1992
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McCarty, P. L., Bachmann, A.. "Canada Patent 1,294,070 Bioconversion Reactor", Leland Stanford Junior University, Jan 7, 1992
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Roberts, P. V., Hopkins, G. D., Semprini, L., and McCarty, P. L.. "United States Patent 5,006,250 Pulsing for Electron Donor and Electron Acceptor for Enhanced Biotransformation of Chemicals", Leland Stanford Junior University, Apr 9, 1991
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Williamson, K. J. and McCarty, P. L.. "United States Patent 4,743,382 Method and Apparatus for Separating Suspended Solids from Liquids", Oregon State University, May 10, 1988
Projects
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Reduction of Greenhouse Gas Production and Energy Consumption in Wastewater Treatment Systems, Inha University, World Class University Program (2008 - 2013)
Ministry of Education, Science, Technology project funded through the National Research Foundation of South Korea
Location
South Korea
Collaborators
- Jaeho Bae, Professor, Environmental Engineering Department, Inha University
2021-22 Courses
All Publications
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Temperate climate energy-positive anaerobic secondary treatment of domestic wastewater at pilot-scale.
Water research
2021; 204: 117598
Abstract
Conventional aerobic secondary treatment of domestic wastewater is energy intensive. Here we report net energy positive operation of a pilot-scale anaerobic secondary treatment system in a temperate climate, with low levels of volatile solids for disposal (<0.15mgVSS/mgCODremoved) and hydraulic residence times as low as 5.3h. This was accomplished with a second-generation staged anaerobic fluidized membrane bioreactor (SAF-MBR 2.0) consisting of a first-stage anaerobic fluidized bed reactor (AFBR) followed by a second-stage gas-sparged anaerobic membrane bioreactor (AnMBR). In stage 1, fluidized granular activated carbon (GAC) particles harbor methanogenic communities that convert soluble biodegradable COD into methane; in stage 2, submerged membranes produce system effluent (permeate) and retain particulate COD that can be hydrolyzed and/or recycled back to stage 1 for conversion to methane. An energy balance on SAF-MBR 2.0 (excluding energy from anaerobic digestion of primary suspended solids) indicated net energy positive operation (+0.11kWh/m3), with energy recovery from produced methane (0.39kWh electricity/m3+0.64kWhheat/m3) exceeding energy consumption due to GAC fluidization (0.07kWh electricity/m3) and gas sparging (0.20kWh electricity/m3 at an optimal flux of 12.2L/m2h). Two factors dominated the operating expenses: energy requirements and recovery cleaning frequency; these factors were in turn affected by flux conditions, membrane fouling rate, and temperature. For optimization of expenses, the frequency of low-cost maintenance cleanings was adjusted to minimize recovery cleanings while maintaining optimal flux with low energy costs. An issue still to be resolved is the occurrence of ultrafine COD in membrane permeate that accounted for much of the total effluent COD.
View details for DOI 10.1016/j.watres.2021.117598
View details for PubMedID 34478994
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What is the Best Biological Process for Nitrogen Removal: When and Why?
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2018; 52 (7): 3835–41
Abstract
Many different aerobic and anaerobic biological processes and treatment schemes are available for transforming organics and/or removing nitrogen from domestic wastewaters. Significant reductions in oxygen requirements and absence of a need for organics for nitrogen reduction are often indicated as advantageous for using the newer anammox organism approach for nitrogen removal rather than the traditional nitrification/denitrification method, the most common one in use today. However, treatment schemes differ, and there are some in which such suggested advantages may not hold. When nitrification/denitrification is used, an anoxic tank is now commonly used first and the nitrate formed by nitrification later is recycled back to that tank for oxidation of wastewater organics. This greatly reduces oxygen requirements and the need for adding organics. So when are such claims correct and when not? What factors in wastewater composition, regulatory requirements, and treatment flow sheet alter which treatment process is best to use? As an aid in making such judgments under different circumstances, the stoichiometry of the different biological processes involved and the different treatment approaches used were determined and compared. Advantages of each as well as imitations and potential opportunities for research to prevent them are presented.
View details for PubMedID 29510030
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Pilot-scale temperate-climate treatment of domestic wastewater with a staged anaerobic fluidized membrane bioreactor (SAF-MBR)
BIORESOURCE TECHNOLOGY
2014; 159: 95-103
Abstract
A pilot-scale staged anaerobic fluidized membrane bioreactor (SAF-MBR) was operated continuously for 485 days, without chemical cleaning of membranes, treating primary-settled domestic wastewater with wastewater temperature between 8 and 30°C and total hydraulic retention time (HRT) between 4.6 and 6.8h. Average chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) removals averaged 81% and 85%, respectively, during the first winter at 8-15°C before full acclimation had occurred. However, subsequently when fully acclimated, summer and winter COD removals of 94% and 90% and BOD5 removals of 98% and 90%, respectively, were obtained with average effluent COD never higher than 23 mg/L nor BOD5 higher than 9 mg/L. Operational energy requirement of 0.23 kW h/m(3) could be met with primary and secondary methane production, and could be reduced further through hydraulic change. Biosolids production in all seasons averaged 0.051 g volatile suspended solids per g COD removed.
View details for DOI 10.1016/j.biortech.2014.02.060
View details for Web of Science ID 000335393500014
View details for PubMedID 24632631
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Effect of temperature on the treatment of domestic wastewater with a staged anaerobic fluidized membrane bioreactor.
Water science and technology
2014; 69 (6): 1145-1150
Abstract
A laboratory staged anaerobic fluidized membrane bioreactor (SAF-MBR) system was applied to the treatment of primary clarifier effluent from a domestic wastewater treatment plant with temperature decreasing from 25 to 10 °C. At all temperatures and with a total hydraulic retention time of 2.3 h, overall chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) removals were 89% and 94% or higher, with permeate COD and BOD5 of 30 and 7 mg/L or lower, respectively. No noticeable negative effects of low temperature on organic removal were found, although a slight increase to 3 mg/L in volatile fatty acids concentrations in the effluent was observed. Biosolids production was 0.01-0.03 kg volatile suspended solids/kg COD, which is far less than that with aerobic processes. Although the rate of trans-membrane pressure at the membrane flux of 9 L/m(2)/h increased as temperature decreased, the SAF-MBR was operated for longer than 200 d before chemical cleaning was needed. Electrical energy potential from combustion of the total methane production (gaseous and dissolved) was more than that required for system operation.
View details for DOI 10.2166/wst.2013.793
View details for PubMedID 24647177
- Stanford's Environmental Engineering & Science Program: The First Fifty Years School of Engineering. Stanford University. 2013 33
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Domestic Wastewater Treatment as a Net Energy Producer-Can This be Achieved?
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2011; 45 (17): 7100-7106
Abstract
In seeking greater sustainability in water resources management, wastewater is now being considered more as a resource than as a waste-a resource for water, for plant nutrients, and for energy. Energy, the primary focus of this article, can be obtained from wastewater's organic as well as from its thermal content. Also, using wastewater's nitrogen and P nutrients for plant fertilization, rather than wasting them, helps offset the high energy cost of producing synthetic fertilizers. Microbial fuel cells offer potential for direct biological conversion of wastewater's organic materials into electricity, although significant improvements are needed for this process to be competitive with anaerobic biological conversion of wastewater organics into biogas, a renewable fuel used in electricity generation. Newer membrane processes coupled with complete anaerobic treatment of wastewater offer the potential for wastewater treatment to become a net generator of energy, rather than the large energy consumer that it is today.
View details for DOI 10.1021/es2014264
View details for Web of Science ID 000294373400002
View details for PubMedID 21749111
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Anaerobic Fluidized Bed Membrane Bioreactor for Wastewater Treatment
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2011; 45 (2): 576-581
Abstract
Anaerobic membrane bioreactors have potential for energy-efficient treatment of domestic and other wastewaters, membrane fouling being a major hurdle to application. It was found that fouling can be controlled if membranes are placed directly in contact with the granular activated carbon (GAC) in an anaerobic fluidized bed bioreactor (AFMBR) used here for post-treatment of effluent from another anaerobic reactor treating dilute wastewater. A 120-d continuous-feed evaluation was conducted using this two-stage anaerobic treatment system operated at 35 °C and fed a synthetic wastewater with chemical oxygen demand (COD) averaging 513 mg/L. The first-stage was a similar fluidized-bed bioreactor without membranes (AFBR), operated at 2.0-2.8 h hydraulic retention time (HRT), and was followed by the above AFMBR, operating at 2.2 h HRT. Successful membrane cleaning was practiced twice. After the second cleaning and membrane flux set at 10 L/m(2)/h, transmembrane pressure increased linearly from 0.075 to only 0.1 bar during the final 40 d of operation. COD removals were 88% and 87% in the respective reactors and 99% overall, with permeate COD of 7 ± 4 mg/L. Total energy required for fluidization for both reactors combined was 0.058 kWh/m(3), which could be satisfied by using only 30% of the gaseous methane energy produced. That of the AFMBR alone was 0.028 kWh/m(3), which is significantly less than reported for other submerged membrane bioreactors with gas sparging for fouling control.
View details for DOI 10.1021/es1027103
View details for Web of Science ID 000286090500038
View details for PubMedID 21158433
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A comparative pilot-scale evaluation of gas-sparged and granular activated carbon-fluidized anaerobic membrane bioreactors for domestic wastewater treatment.
Bioresource technology
2019: 120949
Abstract
Two significantly different pilot-scale AnMBRs were used to treat screened domestic wastewater for over one year. Both systems similarly reduced BOD5 and COD by 86-90% within a 13-32 °C temperature range and at comparable COD loading rates of 1.3-1.4 kg-COD m-3 d-1 and membrane fluxes of 7.6-7.9 L m-2 h-1 (LMH). However, the GAC-fluidized AnMBR achieved these results at a 65% shorter hydraulic retention time than the gas-sparged AnMBR. The gas-sparged AnMBR was able to operate at a similar operating permeability with greater reactor concentrations of suspended solids and colloidal organics than the GAC-fluidized AnMBR. Also, the membranes were damaged more in the GAC-fluidized system. To better capture the relative advantages of each system a hybrid AnMBR comprised of a GAC-fluidized bioreactor connected to a separate gas-sparged ultrafiltration membrane system is proposed. This will likely be more effective, efficient, robust, resilient, and cost-effective.
View details for DOI 10.1016/j.biortech.2019.01.072
View details for PubMedID 31202711
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Efficient anaerobic membrane bioreactor treatment of municipal wastewater for energy and biosolids reduction
AMER CHEMICAL SOC. 2017
View details for Web of Science ID 000430569100630
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Low energy single-staged anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for wastewater treatment.
Bioresource technology
2017
Abstract
An aluminum dioxide (Al2O3) ceramic membrane was used in a single-stage anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for low-strength wastewater treatment. The AFCMBR was operated continuously for 395days at 25°C using a synthetic wastewater having a chemical oxygen demand (COD) averaging 260mg/L. A membrane net flux as high as 14.5-17L/m(2)h was achieved with only periodic maintenance cleaning, obtained by adding 25mg/L of sodium hypochlorite solution. No adverse effect of the maintenance cleaning on organic removal was observed. An average SCOD in the membrane permeate of 23mg/L was achieved with a 1h hydraulic retention time (HRT). Biosolids production averaged 0.014±0.007gVSS/gCOD removed. The estimated electrical energy required to operate the AFCMBR system was 0.039kWh/m(3), which is only about 17% of the electrical energy that could be generated with the methane produced.
View details for DOI 10.1016/j.biortech.2017.03.017
View details for PubMedID 28341380
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Effects of FeCl3 addition on the operation of a staged anaerobic fluidized membrane bioreactor (SAF-MBR)
WATER SCIENCE AND TECHNOLOGY
2016; 74 (1): 130-137
Abstract
The effects on sulfur removal and membrane fouling resulting from FeCl(3) addition to an anaerobic fluidized membrane bioreactor (AFMBR) in a staged AFMBR (SAF-MBR) was investigated. Total sulfur removal in the SAF-MBR was 42-59% without FeCl(3) addition, but increased to 87-95% with FeCl(3) addition. Sulfide removal in the AFMBR increased to 90% with addition of FeCl(3) at a molar Fe(3+)/S ratio of 0.54 and to 95% when the ratio was increased to 0.95. Effluent sulfide concentration then decreased to 0.3-0.6 mg/L. Phosphate removals were only 19 and 37% with the above added FeCl(3) ratios, indicating that iron removed sulfide more readily than phosphate. Neither chemical oxygen demand nor biochemical oxygen demand removal efficiencies were affected by the addition of FeCl(3). When the AFMBR permeate became exposed to air, light brown particles were formed from effluent Fe(2+) oxidation to Fe(3+). FeCl(3) addition, while beneficial for sulfide removal, did increase the membrane fouling rate due to the deposition of inorganic precipitates in the membrane pores.
View details for DOI 10.2166/wst.2016.186
View details for Web of Science ID 000379662100013
View details for PubMedID 27386990
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Integrity of hollow-fiber membranes in a pilot-scale anaerobic fluidized membrane bioreactor (AFMBR) after two-years of operation
SEPARATION AND PURIFICATION TECHNOLOGY
2016; 162: 101-105
View details for DOI 10.1016/j.seppur.2016.02.019
View details for Web of Science ID 000372937400014
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Development and application of a procedure for evaluating the long-term integrity of membranes for the anaerobic fluidized membrane bioreactor (AFMBR).
Water science and technology
2016; 74 (2): 457-465
Abstract
A bench-scale short-term test, developed to predict the long-term integrity of membranes with potential for use in anaerobic fluidized-bed membrane bioreactors, was used to evaluate several commercial hollow-fiber membranes. It was found that membrane performance varied widely, some membranes failing much more rapidly than others. Also found was that larger sizes of the fluidized media, in this case granular activated carbon (GAC), severely affected membrane structural integrity more than did smaller sizes, as did the method used for membrane attachment. Within the limits studied, the GAC packing ratio had only a minor impact. A decrease in membrane permeability that sometimes resulted during the testing and was caused by the deposition of fine GAC particles could be eliminated without membrane damage through simultaneous chemical cleaning and sonication. This new testing procedure should be useful for selecting membranes and reactor operating conditions to better ensure long-term operating performance of anaerobic fluidized-bed membrane bioreactors.
View details for DOI 10.2166/wst.2016.210
View details for PubMedID 27438251
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Discovery of Organohalide-Respiring Processes and the Bacteria Involved
Organohalide-Respiring Bacteria
Springer. 2016: 51–62
View details for DOI 4
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Importance of Dissolved Methane Management When Anaerobically Treating Low-Strength Wastewaters
CURRENT ORGANIC CHEMISTRY
2016; 20 (26): 2810-2816
View details for DOI 10.2174/1385272820666160517155831
View details for Web of Science ID 000386811800008
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Interactions between GAC sizes, particle sizes and biofouling in anaerobic fluidized membrane bioreactor
AMER CHEMICAL SOC. 2015
View details for Web of Science ID 000432475504677
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Anaerobic fluidized membrane bioreactor polishing of baffled reactor effluent during treatment of dilute wastewater
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
2015; 90 (3): 391-397
View details for DOI 10.1002/jctb.4596
View details for Web of Science ID 000349465800005
- Anaerobic Fluidized Bed Membrane Bioreactors for the Treatment of Domestic Wastewater Anaerobic biotechnology: Environmental Protection and Resource Recovery edited by Fang, H. H., Zhang, T. World Scientific. 2015: 211–242
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Superior Removal of Disinfection Byproduct Precursors and Pharmaceuticals from Wastewater in a Staged Anaerobic Fluidized Membrane Bioreactor Compared to Activated Sludge
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
2014; 1 (11): 459-464
View details for DOI 10.1021/ez500279a
View details for Web of Science ID 000350831700005
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The effect of fluidized media characteristics on membrane fouling and energy consumption in anaerobic fluidized membrane bioreactors
SEPARATION AND PURIFICATION TECHNOLOGY
2014; 132: 10-15
View details for DOI 10.1016/j.seppur.2014.04.049
View details for Web of Science ID 000340300600002
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Anaerobic treatment of low-strength wastewater: A comparison between single and staged anaerobic fluidized bed membrane bioreactors
BIORESOURCE TECHNOLOGY
2014; 165: 75-80
Abstract
Performance of a single anaerobic fluidized membrane bioreactor (AFMBR) was compared with that of a staged anaerobic fluidized membrane bioreactor system (SAF-MBR) that consisted of an anaerobic fluidized bed bioreactor (AFBR) followed by an AFMBR. Both systems were fed with an equal COD mixture (200mg/L) of acetate and propionate at 25°C. COD removals of 93-96% were obtained by both systems, independent of the hydraulic retention times (HRT) of 2-4h. Over more than 200d of continuous operation, trans-membrane pressure (TMP) in both systems was less than 0.2bar without significant membrane fouling as a result of the scouring of membrane surfaces by the moving granular activated carbon particles. Results of bulk liquid suspended solids, extracellular polymeric substances (EPS), and soluble microbial products (SMP) analyses also revealed no significant differences between the two systems, indicating the single AFMBR is an effective alternative to the SAF-MBR system.
View details for DOI 10.1016/j.biortech.2014.02.065
View details for Web of Science ID 000338710700013
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Anaerobic treatment of low-strength wastewater: A comparison between single and staged anaerobic fluidized bed membrane bioreactors.
Bioresource technology
2014; 165: 75-80
Abstract
Performance of a single anaerobic fluidized membrane bioreactor (AFMBR) was compared with that of a staged anaerobic fluidized membrane bioreactor system (SAF-MBR) that consisted of an anaerobic fluidized bed bioreactor (AFBR) followed by an AFMBR. Both systems were fed with an equal COD mixture (200mg/L) of acetate and propionate at 25°C. COD removals of 93-96% were obtained by both systems, independent of the hydraulic retention times (HRT) of 2-4h. Over more than 200d of continuous operation, trans-membrane pressure (TMP) in both systems was less than 0.2bar without significant membrane fouling as a result of the scouring of membrane surfaces by the moving granular activated carbon particles. Results of bulk liquid suspended solids, extracellular polymeric substances (EPS), and soluble microbial products (SMP) analyses also revealed no significant differences between the two systems, indicating the single AFMBR is an effective alternative to the SAF-MBR system.
View details for DOI 10.1016/j.biortech.2014.02.065
View details for PubMedID 24630367
- Discovery of Organohalide-Respiring Processes and the Bacteria Involved Discovery of Organohalide-Respiring Processes and the Bacteria Involved edited by Adrian, L., Löffler, F. E. Springer. 2014: 51–62
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The effect of SRT on nitrate formation during autotrophic nitrogen removal of anaerobically treated wastewater
WATER SCIENCE AND TECHNOLOGY
2013; 68 (8): 1751-1756
Abstract
Autotrophic nitrogen removal, coupling nitritation (ammonium to nitrite) with anaerobic ammonium oxidation (anammox), offers a promising nitrogen-removal alternative, especially for post-treatment of anaerobically-treated wastewater. However, previous reports suggest that less than 90% total nitrogen removal should be expected with this process alone because over 10% of the ammonium removed will be converted to nitrate. This is caused because nitrite conversion to nitrate is required for reduction of carbon dioxide to cell carbon. However, recent research results suggest that more limited nitrate formation of only a few per cent sometimes occurs. It was hypothesized such lower nitrate yields may result from use of long solids retention times (SRT) where net biological yields are low, and providing that the ratio of oxygen added to influent ammonium concentrations is maintained at or below 0.75 mol/mol. Overall reaction equations were developed for each process and combined to evaluate the potential effect of SRT on process stoichiometry. The results support the use of a long SRT to reduce net cell yield, which in turn results in a small percentage conversion to nitrate during ammonium removal and high total nitrogen removals in the range of 90 to 94%.
View details for DOI 10.2166/wst.2013.368
View details for Web of Science ID 000327140500010
View details for PubMedID 24185056
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Two-stage anaerobic fluidized-bed membrane bioreactor treatment of settled domestic wastewater
WATER SCIENCE AND TECHNOLOGY
2013; 68 (2): 394-399
Abstract
A two-stage anaerobic fluidized-bed membrane bioreactor (SAF-MBR) system was applied for the treatment of primary-settled domestic wastewater that was further pre-treated by either 10 μm filtration or 1 mm screening. While the different pre-treatment options resulted in different influent qualities, the effluent qualities were quite similar. In both cases at a total hydraulic retention time of 2.3 h and 25 °C, chemical oxygen demand and biochemical oxygen demand (BOD5) removals were 84-91% and 92-94%, with effluent concentrations lower than 25 and 7 mg/L, respectively. With a membrane flux of 6-12 L/m(2)/h, trans-membrane pressure remained below 0.2 bar during 310 d of continuous operation without need for membrane chemical cleaning or backwashing. Biosolids production was estimated to be 0.028-0.049 g volatile suspended solids/g BOD5, which is far less than that with comparable aerobic processes. Electrical energy production from combined heat and power utilization of the total methane produced (gaseous and dissolved) was estimated to be more than sufficient for total system operation.
View details for DOI 10.2166/wst.2013.191
View details for Web of Science ID 000322886600018
View details for PubMedID 23863433
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Efficient single-stage autotrophic nitrogen removal with dilute wastewater through oxygen supply control
BIORESOURCE TECHNOLOGY
2012; 123: 400-405
Abstract
Autotrophic nitrogen removal via ammonia oxidizing (AOB) and anaerobic ammonium oxidizing (anammox) bacteria was evaluated for treatment of a dilute 50mg/L ammonia-containing solution in a single-stage nitrogen-removal filter at 25°C. Important was an external oxygenation system that permitted close control and measurement of oxygen supply, a difficulty with the generally used diffused air systems. Hydraulic retention time (HRT) was reduced in steps from 15 to 1h. At 1h HRT, total nitrogen (TN) removals varied between 73% and 94%, the maximum being obtained with a benchmark oxygenation ratio of 0.75mol O(2)/mol ammonia fed. At higher ratios, nitrate was formed causing TN removal efficiency to decrease. With lower ratios, TN and ammonia removals decreased in proportion to the decrease in BOR. When operating at or below the BOR, nitrate formation equaled no more than 2% of the ammonia removed, a value much less than has previously been reported.
View details for DOI 10.1016/j.biortech.2012.07.076
View details for Web of Science ID 000310401100059
View details for PubMedID 22940348
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Anaerobic treatment of municipal wastewater with a staged anaerobic fluidized membrane bioreactor (SAF-MBR) system
BIORESOURCE TECHNOLOGY
2012; 120: 133-139
Abstract
A laboratory-scale staged anaerobic fluidized membrane bioreactor (SAF-MBR) system was used to treat a municipal wastewater primary-clarifier effluent. It was operated continuously for 192 days at 6-11 L/m(2)/h flux and trans-membrane pressure generally of 0.1 bar or less with no fouling control except the scouring effect of the fluidized granular activated carbon on membrane surfaces. With a total hydraulic retention time of 2.3h at 25°C, the average effluent chemical oxygen demand and biochemical oxygen demand concentrations of 25 and 7 mg/L yielded corresponding removals of 84% and 92%, respectively. Also, near complete removal of suspended solids was obtained. Biosolids production, representing 5% of the COD removed, equaled 0.049 g VSS/g BOD(5) removed, far less than the case with comparable aerobic processes. The electrical energy required for the operation of the SAF-MBR system, 0.047 kW h/m(3), could be more than satisfied by using the methane produced.
View details for DOI 10.1016/j.biortech.2012.06.028
View details for Web of Science ID 000308056000020
View details for PubMedID 22784964
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Lower operational limits to volatile fatty acid degradation with dilute wastewaters in an anaerobic fluidized bed reactor
BIORESOURCE TECHNOLOGY
2012; 109: 13-20
Abstract
A general concern that anaerobic treatment of dilute wastewaters is limited by the inability of methanogenic and related syntrophic organisms to reduce substrate concentrations adequately was evaluated using a 35 °C granular activated carbon-containing laboratory-scale fluidized bed reactor fed an acetate-propionate equal chemical oxygen demand (COD) mixture synthetic wastewater. Contrary to general expectations, effluent acetate and propionate concentrations remained near or below their detection limits of 0.4 mg COD/L with influent COD of 200mg/L, 17 min hydraulic retention time, and organic loading as high as 17 kg COD/m(3)d, or with influent COD values ranging from 45 to 2010 mg COD/L and organic loadings of 4.2-4.5 kg COD/m(3)d. The effluent acetate concentrations in these well-fed systems were at or much below reported threshold limits for starving non-fed cultures, suggesting that a better understanding of threshold values and factors affecting treatment efficiency with anaerobic treatment of dilute wastewaters is needed.
View details for DOI 10.1016/j.biortech.2012.01.014
View details for Web of Science ID 000301810500003
View details for PubMedID 22285295
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Energy-efficient anaerobic membrane bioreactor for treatment of dilute wastewaters
AMER CHEMICAL SOC. 2012
View details for Web of Science ID 000324475104811
- Introduction Delivery and Mixing in the Subsurface: Processes and Design Principles for In-Situ Remediation edited by Kitanidis, P. K., McCarty, P. L. Springer. 2012: 1
- Chemical and Biological Processes – The Need for Mixing Delivery and Mixing in the Subsurface: Processes and Design Principles for In-Situ Remediation edited by Kitanidis, P., McCarty, P. L. Springer. 2012: 2
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CHEMICAL AND BIOLOGICAL PROCESSES: THE NEED FOR MIXING
DELIVERY AND MIXING IN THE SUBSURFACE: PROCESSES AND DESIGN PRINCIPLES FOR IN SITU REMEDIATION
2012: 7–52
View details for DOI 10.1007/978-1-4614-2239-6_2
View details for Web of Science ID 000303409300002
- Delivery and Mixing in the Subsurface: Processes and Design Principles for In Situ Remediation edited by Kitanidis, P. K., McCarty, P. L. Springer. 2012
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Effects of influent DO/COD ratio on the performance of an anaerobic fluidized bed reactor fed low-strength synthetic wastewater
BIORESOURCE TECHNOLOGY
2011; 102 (21): 9860-9865
Abstract
The effect of influent DO/COD (dissolved oxygen/chemical oxygen demand) ratio on the performance of an anaerobic fluidized bed reactor (AFBR) containing GAC was studied. A high influent DO concentration was found to have adverse impacts on organic removal efficiency, methane production, and effluent suspended solids (SS) concentration. These problems resulted with a DO/COD ratio of 0.12, but not at a lower ratio of 0.05. At first organic removal appeared satisfactory at the higher DO/COD ratio at a hydraulic retention time of 0.30 h, but soon a rapid growth of oxygen-consuming zoogloeal-like organisms resulted, eventually causing high effluent SS concentrations. The influent DO also had an inhibitory effect, resulting in a long recovery time for adequate methanogenic activity to return after influent DO removal began. With the growing interest in anaerobic treatment of low COD wastewaters, the increased possibility of similar adverse DO effects occurring needs consideration.
View details for DOI 10.1016/j.biortech.2011.07.109
View details for Web of Science ID 000296124200005
View details for PubMedID 21906938
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Model to Couple Anaerobic Process Kinetics with Biological Growth Equilibrium Thermodynamics
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2011; 45 (16): 6838-6844
Abstract
Monod kinetics indicates a substrate concentration limit (S(min)) at biological growth equilibrium where growth is just balanced by decay. A relationship between S(min) and the Gibbs free energy available at growth equilibrium (ΔG(E)) was introduced into the Monod model and applied directly to chemostat cultures. Results from four anaerobic mixed-culture chemostat studies yielded ΔG(E) of -17.7 ± 2.2 kJ/mol acetate converted to methane. ΔG(E) for propionate syntrophs in propionate-fed cultures was -8.0 ± 3.1 kJ/mol propionate, compared with that of -3.0 ± 0.9 kJ/mol H(2) for the hydrogenotrophs present. With ethanol present, however, ΔG(E) for the hydrogenotrophs became more favorable, -6.1 ± 1.6 kJ/mol H(2), while ΔG(E) for propionate became positive even though propionate was consumed, suggesting an alternative interspecies electron transport route. The results suggest that S(min), normally considered a function of an organism's intrinsic rate characteristics, is also a function of solution characteristics, and this is likely the case for the substrate affinity coefficient, K, as well. A comparison between ΔG(E) and S(min) and reported threshold thermodynamic and concentration limits, leads to the conclusion that ΔG(E) and S(min) represent lower and upper bounds, respectively, on such values. This study indicates that knowledge gained from pure-culture studies applies well to more complex natural anaerobic systems.
View details for DOI 10.1021/es2009055
View details for Web of Science ID 000293758400017
View details for PubMedID 21740015
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Biological reduction of chlorinated solvents: Batch-scale geochemical modeling
ADVANCES IN WATER RESOURCES
2010; 33 (9): 969-986
View details for DOI 10.1016/j.advwatres.2010.04.017
View details for Web of Science ID 000283967400002
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Groundwater Contamination by Chlorinated Solvents: History, Remediation Technologies and Strategies
In Situ Remediation of Chlorinated Solvent Plumes
edited by Stroo, H. F., Ward, C. H.
Springer. 2010: 1–28
View details for DOI 1
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pH control for enhanced reductive bioremediation of chlorinated solvent source zones
SCIENCE OF THE TOTAL ENVIRONMENT
2009; 407 (16): 4560-4573
Abstract
Enhanced reductive dehalogenation is an attractive treatment technology for in situ remediation of chlorinated solvent DNAPL source areas. Reductive dehalogenation is an acid-forming process with hydrochloric acid and also organic acids from fermentation of the electron donors typically building up in the source zone during remediation. This can lead to groundwater acidification thereby inhibiting the activity of dehalogenating microorganisms. Where the soils' natural buffering capacity is likely to be exceeded, the addition of an external source of alkalinity is needed to ensure sustained dehalogenation. To assist in the design of bioremediation systems, an abiotic geochemical model was developed to provide insight into the processes influencing the groundwater acidity as dehalogenation proceeds, and to predict the amount of bicarbonate required to maintain the pH at a suitable level for dehalogenating bacteria (i.e., >6.5). The model accounts for the amount of chlorinated solvent degraded, site water chemistry, electron donor, alternative terminal electron-accepting processes, gas release and soil mineralogy. While calcite and iron oxides were shown to be the key minerals influencing the soil's buffering capacity, for the extensive dehalogenation likely to occur in a DNAPL source zone, significant bicarbonate addition may be necessary even in soils that are naturally well buffered. Results indicated that the bicarbonate requirement strongly depends on the electron donor used and availability of competing electron acceptors (e.g., sulfate, iron (III)). Based on understanding gained from this model, a simplified model was developed for calculating a preliminary design estimate of the bicarbonate addition required to control the pH for user-specified operating conditions.
View details for DOI 10.1016/j.scitotenv.2009.03.029
View details for Web of Science ID 000267839200002
View details for PubMedID 19464727
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Bioaugmentation with butane-utilizing microorganisms to promote in situ cometabolic treatment of 1,1,1-trichloroethane and 1,1-dichloroethene
JOURNAL OF CONTAMINANT HYDROLOGY
2009; 103 (3-4): 157-167
Abstract
A field study was performed to evaluate the potential for in-situ aerobic cometabolism of 1,1,1-trichloroethane (1,1,1-TCA) through bioaugmentation with a butane enrichment culture containing predominantly two Rhodococcus sp. strains named 179BP and 183BP that could cometabolize 1,1,1-TCA and 1,1-dicholoroethene (1,1-DCE). Batch tests indicated that 1,1-DCE was more rapidly transformed than 1,1,1-TCA by both strains with 183BP being the most effective organism. This second in a series of bioaugmentation field studies was conducted in the saturated zone at the Moffett Field In Situ Test Facility in California. In the previous test, bioaugmentation with an enrichment culture containing the 183BP strain achieved short term in situ treatment of 1,1-DCE, 1,1,1-TCA, and 1,1-dichloroethane (1,1-DCA). However, transformation activity towards 1,1,1-TCA was lost over the course of the study. The goal of this second study was to determine if more effective and long-term treatment of 1,1,1-TCA could be achieved through bioaugmentation with a highly enriched culture containing 179BP and 183BP strains. Upon bioaugmentation and continuous addition of butane and dissolved oxygen and or hydrogen peroxide as sources of dissolved oxygen, about 70% removal of 1,1,1-TCA was initially achieved. 1,1-DCE that was present as a trace contaminant was also effectively removed (approximately 80%). No removal of 1,1,1-TCA resulted in a control test leg that was not bioaugmented, although butane and oxygen consumption by the indigenous populations was similar to that in the bioaugmented test leg. However, with prolonged treatment, removal of 1,1,1-TCA in the bioaugmented leg decreased to about 50 to 60%. Hydrogen pexoxide (H2O2) injection increased dissolved oxygen concentration, thus permitting more butane addition into the test zone, but more effective 1,1,1-TCA treatment did not result. The results showed bioaugmentation with the enrichment cultures was effective in enhancing the cometabolic treatment of 1,1,1-TCA and low concentrations of 1,1-DCE over the entire period of the 50-day test. Compared to the first season of testing, cometabolic treatment of 1,1,1-TCA was not lost. The better performance achieved in the second season of testing may be attributed to less 1,1-DCE transformation product toxicity, more effective addition of butane, and bioaugmentation with the highly enriched dual culture.
View details for DOI 10.1016/j.jconhyd.2008.10.005
View details for Web of Science ID 000263009100008
View details for PubMedID 19022526
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Comparison between acetate and hydrogen as electron donors and implications for the reductive dehalogenation of PCE and TCE
JOURNAL OF CONTAMINANT HYDROLOGY
2007; 94 (1-2): 76-85
Abstract
Bioremediation by reductive dehalogenation of groundwater contaminated with tetrachloroethene (PCE) or trichloroethene (TCE) is generally carried out through the addition of a fermentable electron donor such as lactate, benzoate, carbohydrates or vegetable oil. These fermentable donors are converted by fermenting organisms into acetate and hydrogen, either of which might be used by dehalogenating microorganisms. Comparisons were made between H2 and acetate on the rate and extent of reductive dehalogenation of PCE. PCE dehalogenation with H2 alone was complete to ethene, but with acetate alone it generally proceeded only about half as fast and only to cis-1,2-dichloroethene (cDCE). Additionally, acetate was not used as an electron donor in the presence of H2. These findings suggest the fermentable electron donor requirement for PCE dehalogenation to ethene can be reduced up to 50% by separating PCE dehalogenation into two stages, the first of which uses acetate for the conversion of PCE to cDCE, and the second uses H2 for the conversion of cDCE to ethene. This can be implemented with a recycle system in which the fermentable substrate is added down-gradient, where the hydrogen being produced by fermentation effects cDCE conversion into ethene. The acetate produced is recycled up-gradient to achieve PCE conversion into cDCE. With the lower electron donor usage required, potential problems of aquifer clogging, excess methane production, and high groundwater chemical oxygen demand (COD) can be greatly reduced.
View details for DOI 10.1016/j.jconhyd.2007.05.003
View details for Web of Science ID 000250767600005
View details for PubMedID 17610987
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Dependence of lumped mass transfer coefficient on scale and reactions kinetics for biologically enhanced NAPL dissolution
ADVANCES IN WATER RESOURCES
2007; 30 (6-7): 1618-1629
View details for DOI 10.1016/j.advwatres.2006.06.016
View details for Web of Science ID 000246902300017
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Thermodynamic electron equivalents model for bacterial yield prediction: Modifications and comparative evaluations
BIOTECHNOLOGY AND BIOENGINEERING
2007; 97 (2): 377-388
Abstract
Modifications are made to an earlier thermodynamic model (TEEM1) for prediction of maximum microbial yields from aerobic and anaerobic as well as heterotrophic and autotrophic growth. The revised model (TEEM2) corrects for lower yields found with aerobic oxidations of organic compounds where an oxygenase is involved and with growth on single-carbon (C1) compounds. TEEM1 and TEEM2 are based on energy release and consumption as determined from the reduction potential or Gibbs free energy of (1/2)-reaction reduction equations together with losses of energy during energy transfer. Energy transfer efficiency is a key parameter needed to make predictions with TEEM2, and was determined through evaluations with extensive data sets on aerobic heterotrophic yield available in the literature. For compounds following normal catabolic pathways, the best-fit value for energy transfer efficiency was 0.37, which permitted accurate predictions of growth with a precision of 15%-20% as determined by standard deviation. Using the same energy transfer efficiency, a similar precision, but somewhat less accuracy was found for organic compounds where oxidation involves an oxygenase (estimates 8% too high) and for C1 compounds (estimates 17% too high). In spite of the somewhat lower accuracy, the TEEM2 modifications resulted in improved predictions over TEEM1 and the comparison models.
View details for DOI 10.1002/bit.21250
View details for Web of Science ID 000246434700017
View details for PubMedID 17089390
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Laboratory, field, and modeling studies of bioaugmentation of butane-utilizing microorganisms for the in situ cometabolic treatment of 1,1-dichloroethene, 1,1-dichloroethane, and 1,1,1-trichloroethane
ADVANCES IN WATER RESOURCES
2007; 30 (6-7): 1528-1546
View details for DOI 10.1016/j.advwatres.2006.05.017
View details for Web of Science ID 000246902300010
- Electron Donor and pH Relationships for Biologically Enhanced Dissolution of Chlorinated Solvent DNAPL in Groundwater European Journal of Soil Biology 2007; 43: 276-282
- Bioaugmentation of Butane-Utilizing Microorganisms for the In Situ Cometabolic Treatment of 1,1-Dichloroethene, 1,1-Dichloroethane, and 1,1,1-Trichloroethane European Journal of Soil Biology 2007; 43: 322-327
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Field evaluation of in situ source reduction of trichloroethylene in groundwater using bioenhanced in-well vapor stripping
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2005; 39 (22): 8963-8970
Abstract
Two technologies in combination, cometabolic bioremediation and in-well vapor stripping, were applied to reduce trichloroethylene (TCE) concentrations in groundwater at a contaminant source area without the need to pump contaminated groundwater to the surface for treatment. The vapor-stripping well reduced source TCE concentrations (as high as 6-9 mg/L) by over 95%. Effluent from the well then flowed to two bioremediation wells, where additional reductions of approximately 60% were achieved. TCE removal was extensively monitored (for research and not regulatory purposes) using an automated system that collected samples about every 45 min at 55 locations over an area of approximately 50 x 60 m2. During 4.5 months of system operation, total TCE mass removal was 8.1 kg, 7.1 kg of which resulted from in-well vapor stripping and 1.0 kg from biotreatment. The system reduced the average TCE concentration of about 3000 microg/L in the source-zone groundwater to about 250 microg/L in water leaving the treatment zone, effecting greater than 92% TCE removal. A 6 month rebound study after system operation ceased found TCE concentrations then increased significantly in the treatment zone due to diffusion from the fractured rock below and perhaps other processes, with mass increases of about 1.5 kg in the lower aquifer and 0.3 kg in the upper aquifer.
View details for DOI 10.1021/es050628f
View details for Web of Science ID 000233297100061
View details for PubMedID 16323801
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Medical bioremediation: Prospects for the application of microbial catabolic diversity to aging and several major age-related diseases
AGEING RESEARCH REVIEWS
2005; 4 (3): 315-338
Abstract
Several major diseases of old age, including atherosclerosis, macular degeneration and neurodegenerative diseases are associated with the intracellular accumulation of substances that impair cellular function and viability. Moreover, the accumulation of lipofuscin, a substance that may have similarly deleterious effects, is one of the most universal markers of aging in postmitotic cells. Reversing this accumulation may thus be valuable, but has proven challenging, doubtless because substances resistant to cellular catabolism are inherently hard to degrade. We suggest a radically new approach: augmenting humans' natural catabolic machinery with microbial enzymes. Many recalcitrant organic molecules are naturally degraded in the soil. Since the soil in certain environments - graveyards, for example - is enriched in human remains but does not accumulate these substances, it presumably harbours microbes that degrade them. The enzymes responsible could be identified and engineered to metabolise these substances in vivo. Here, we survey a range of such substances, their putative roles in age-related diseases and the possible benefits of their removal. We discuss how microbes capable of degrading them can be isolated, characterised and their relevant enzymes engineered for this purpose and ways to avoid potential side-effects.
View details for DOI 10.1016/j.arr.2005.03.008
View details for Web of Science ID 000232100700001
View details for PubMedID 16040282
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Modeling microbial reactions at the plume fringe subject to transverse mixing in porous media: When can the rates of microbial reaction be assumed to be instantaneous?
WATER RESOURCES RESEARCH
2005; 41 (6)
View details for DOI 10.1029/2004WR003495
View details for Web of Science ID 000229832500001
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Numerical model for biological fluidized-bed reactor treatment of perchlorate-contaminated groundwater
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2005; 39 (3): 850-858
Abstract
Biological fluidized-bed reactor (BFBR) treatment with 1.3 mm granular activated carbon as support medium is being used for removal of 2.6 mg/L perchlorate from contaminated groundwater in California. The California drinking-water action level of 4 microg/L for perchlorate requires 99.9% perchlorate removal. Sufficient ethanol, the electron donor, is added to remove oxygen and nitrate as well as perchlorate, as all three serve as electron acceptors, but with biological preference for oxygen and nitrate. A numerical BFBR model based upon basic physical, chemical, and biological processes including reaction stoichiometry, biofilm kinetics, and sequential electron acceptor usage was developed and evaluated with the full-scale treatment results. A key fitting parameter was bacterial detachment rate, which impacts reaction stoichiometry. For best model fit this was found to vary between 0.062 and 0.31 d(-1), with an average of 0.22 d(-1). The model indicates that GAC particle size, reactor diameter, and perchlorate concentration affect BFBR performance. While empty-bed detention time might be decreased somewhat below 10 min by an increase in either GAC particle size or reactor diameter, the current design provides a good factor of safety in operation. With a 10 min detention time, the effluent goal of 4 microg/L should be achievable even with influent perchlorate concentration as high as 10 mg/L.
View details for DOI 10.1021/es040303j
View details for Web of Science ID 000226712600034
View details for PubMedID 15757349
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Simulated and experimental evaluation of factors affecting the rate and extent of reductive dehalogenation of chloroethenes with glucose
JOURNAL OF CONTAMINANT HYDROLOGY
2004; 74 (1-4): 313-331
Abstract
Carbohydrates such as molasses are being added to aquifers to serve as electron donors for reductive dehalogenation of chloroethenes. Glucose, as a model carbohydrate, was studied to better understand the processes involved and to evaluate the effectiveness for dehalogenation of different approaches for carbohydrate addition. A simulation model was developed and calibrated with experimental data for the reductive dehalogenation of tetrachloroethene to ethene via cis-1,2-dichloroethene. The model included fermentors that convert the primary donor (glucose) into butyrate, acetate and hydrogen, methanogens, and two separate dehalogenator groups. The dehalogenation groups use the hydrogen intermediate as an electron donor and the different haloethenes as electron acceptors through competitive inhibition. Model simulations suggest first that the initial relative population size of dehalogenators and H(2)-utilizing methanogens greatly affects the degree of dehalogenation achieved. Second, the growth and decay of biomass from soluble carbohydrate plays a significant role in reductive dehalogenation. Finally, the carbohydrate delivery strategies used (periodic versus batch addition and the time interval between periodic addition) greatly affect the degree of dehalogenation that can be obtained with a given amount of added carbohydrate.
View details for DOI 10.1016/j.jconhyd.2004.03.006
View details for Web of Science ID 000224186500016
View details for PubMedID 15358499
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Comparative evaluation of chloroethene dechlorination to ethene by Dehalococcoides-like microorganisms
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2004; 38 (18): 4768-4774
Abstract
Reductive dehalogenation of tetrachloroethene (PCE), trichloroethene (TCE), cis-1,2-dichloroethene (DCE), and vinyl chloride (VC) was examined in four cultures containing Dehalococcoides-like microorganisms. Dechlorination and growth kinetics were compared using a Monod growth-rate model for multiple electron acceptor usage with competition. Included were the Victoria mixed culture containing Dehalococcoides species strain VS (from Victoria, TX), the mixed culture KB-1/VC (from southern Ontario), the Pinellas mixed culture (from Pinellas, FL), and D. ethenogenes strain 195. All cultures, with the exception of D. ethenogenes strain 195, grew with VC as catabolic electron acceptor. A dilution method was developed that allows a valid comparison to be made of dehalogenating kinetics between different mixed cultures. Using this procedure, maximum growth rates on VC were found to be similar for strain VS and KB-1/VC (0.42-0.49 +/- 0.02 d(-1)) but slower for the Pinellas culture (0.28 +/- 0.01 d(-1)). The 16S rRNA gene sequences were determined to ensure that no cross contamination between cultures had occurred. Following enrichment of the VC dechlorinating microorganisms on VC, the cultures were amended with DCE, TCE, or PCE. The three mixed cultures failed to dechlorinate PCE or did so very slowly. However, the dilution technique indicated that all experienced growth on TCE and DCE as well as on VC. Maximum growth rates on DCE alone were quite similar (0.43-0.46 d(-1)), while the Pinellas culture grew faster on TCE alone (0.49 d(-1)) than did the other two mixed cultures (0.33-0.35 d(-1)). Half-velocity and inhibition constants for growth on TCE were also determined for the three mixed cultures; both constants were found to be essentially equal and the same for the different cultures, varying between only 8.6 and 10.5 microM. The ability of the strain VS, KB-1/VC, and Pinellas cultures to utilize TCE rapidly with conversion to ethene is quite different from that of any other reported microorganism. It was separately confirmed with more traditional cell-counting techniques that strain VS coupled TCE, as well as DCE and VC, utilization with growth. This is the first report of an organism obtaining energy for growth through every step in the reduction of TCE to ethene. Also, as suggested by the dilution technique, the dehalogenating organisms in the KB-1/VC and Pinellas cultures appear to obtain growth from TCE utilization as well. Such ability to grow while dehalogenating TCE to ethene will be an important advantage for their use in bioaugmentation.
View details for DOI 10.1021/es049965z
View details for Web of Science ID 000223938500016
View details for PubMedID 15487786
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Molecular identification of the catabolic vinyl chloride reductase from Dehalococcoides sp strain VS and its environmental distribution
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
2004; 70 (8): 4880-4888
Abstract
Reductive dehalogenation of vinyl chloride (VC) to ethene is the key step in complete anaerobic degradation of chlorinated ethenes. VC-reductive dehalogenase was partially purified from a highly enriched culture of the VC-respiring Dehalococcoides sp. strain VS. The enzyme reduced VC and all dichloroethene (DCE) isomers, but not tetrachloroethene (PCE) or trichloroethene (TCE), at high rates. By using reversed genetics, the corresponding gene (vcrA) was isolated and characterized. Based on the predicted amino acid sequence, VC reductase is a novel member of the family of corrinoid/iron-sulfur cluster containing reductive dehalogenases. The vcrA gene was found to be cotranscribed with vcrB, encoding a small hydrophobic protein presumably acting as membrane anchor for VC reductase, and vcrC, encoding a protein with similarity to transcriptional regulators of the NosR/NirI family. The vcrAB genes were subsequently found to be present and expressed in other cultures containing VC-respiring Dehalococcoides organisms and could be detected in water samples from a field site contaminated with chlorinated ethenes. Therefore, the vcrA gene identified here may be a useful molecular target for evaluating, predicting, and monitoring in situ reductive VC dehalogenation.
View details for DOI 10.1128/AEM.70.8.4880-4888.2004
View details for Web of Science ID 000223290100061
View details for PubMedID 15294827
View details for PubMedCentralID PMC492378
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Possible factors controlling the effectiveness of bioenhanced dissolution of non-aqueous phase tetrachloroethene
ADVANCES IN WATER RESOURCES
2004; 27 (6): 601-615
View details for DOI 10.1016/j.advwatres.2004.03.002
View details for Web of Science ID 000221814200003
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Vinyl chloride and cis-dichloroethene dechlorination kinetics and microorganism growth under substrate limiting conditions
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2004; 38 (4): 1102-1107
Abstract
The reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE) at contaminated sites often results in the accumulation of cis-1,2-dichloroethene (DCE) and vinyl chloride (VC), rather than the nonhazardous end product ethene. This accumulation may be caused by the absence of appropriate microorganisms, insufficient supply of donor substrate, or reaction kinetic limitations. Here, we address the issue of reaction kinetic limitations by investigating the effect of limiting substrate concentrations (electron donor and acceptor) on DCE and VC dechlorination kinetics and microorganism growth by bacterium VS. For this, a model based on Monod kinetics, but also accounting for competition between electron acceptors and the effect of low electron donor and acceptor concentrations (dual-substrate kinetics), was examined. Competitive coefficients for VC (7.8 +/- 1.5 microM) and DCE (3.6 +/- 1.1 microM) were obtained and included in the model. The half velocity coefficient for hydrogen, the electron donor, was experimentally determined (7 +/- 2 nM) through investigating dechlorination over different substrate concentrations. This complete model was then used, along with experimental data, to determine substrate concentrations at which the dechlorinating microorganisms would be in net decay. Notably, the model indicates net decay will result if the total electron acceptor concentration (DCE plus VC) is below 0.7 microM, regardless of electron donor levels. The ability to achieve sustainable bioremediation to acceptable levels can be greatly influenced by this threshold level.
View details for DOI 10.1021/es0348647
View details for Web of Science ID 000188996600025
View details for PubMedID 14998024
- Natural Attenuation Hebrew Journal of Water and Environment 2004; 60: 19-20, 60-64
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Effects of biomass accumulation on microbially enhanced dissolution of a PCE pool: a numerical simulation
JOURNAL OF CONTAMINANT HYDROLOGY
2003; 65 (1-2): 79-100
Abstract
Recent studies have shown that dechlorinating bacteria can accelerate the dissolution rate of dense, nonaqueous phase liquids (DNAPLs) containing tetrachloroethene (PCE). We present an advection-dispersion-reaction model for a two-dimensional domain, with groundwater flowing over a pool of free-product PCE. PCE is converted to cis-1,2-dichloroethene (cDCE) and toxicity due to PCE or cDCE is neglected. We adopt previously published correlations relating biomass concentrations and hydraulic conductivity, accounting for biofilm growth and plug-like growth. The system of coupled equations is solved numerically. The high biotransformation rate of PCE increases the concentration gradient of PCE at the water-DNAPL interface, enhancing dissolution. The higher the electron donor (ED) concentration, the larger the dissolution enhancement. Based on the values of maximum specific rate we used, when the electron donor is unlimited, the active biomass accumulates adjacent to the water-NAPL interface and microbial reactions can significantly enhance the pool dissolution. The resulting steady-state dissolution rate can be approximated by a half-order solution when zero-order kinetics are suitable for representing the microbial reaction. However, bioclogging may significantly reduce local hydraulic conductivity; thus, it decreases the flow near the water-DNAPL interface, decreasing dissolution. When the ED is the limiting factor, active biomass accumulates away from the interface. This creates a no-flow zone between the active biomass and the interface. The enlargement of the no-flow zone, due to the donor limitation, diminishes the concentration gradient and the flushing around the water-DNAPL interface. Such adverse impacts may significantly decrease the enhancement predicted by models that do not consider the effects of bioclogging.
View details for DOI 10.1016/S0169-7722(02)00232-2
View details for Web of Science ID 000184322200005
View details for PubMedID 12855202
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Response to comment on "Comparison between donor substrates for biologically enhanced tetrachloroethene DNAPL dissolution"
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2003; 37 (11): 2620-2621
View details for DOI 10.1021/es030395x
View details for Web of Science ID 000183242300065
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Growth of a Dehalococcoides-like microorganism on vinyl chloride and cis-dichloroethene as electron acceptors as determined by competitive PCR
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
2003; 69 (2): 953-959
Abstract
A competitive PCR (cPCR) assay targeting 16S ribosomal DNA was developed to enumerate growth of a Dehalococcoides-like microorganism, bacterium VS, from a mixed culture catalyzing the reductive dehalogenation of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), with hydrogen being used as an electron donor. The growth of bacterium VS was found to be coupled to the dehalogenation of VC and cDCE, suggesting unique metabolic capabilities. The average growth yield was (5.2 +/- 1.5) x 10(8) copies of the 16S rRNA gene/ micromol of Cl(-) (number of samples, 10), with VC being used as the electron acceptor and hydrogen as the electron donor. The maximum VC utilization rate (q) was determined to be 7.8 x 10(-10) micromol of Cl(-) (copy(-1) day(-1)), indicating a maximum growth rate of 0.4 day(-1). These average growth yield and q values agree well with values found previously for dechlorinating cultures. Decay coefficients were determined with growth (0.05 day(-1)) and no-growth (0.09 day(-1)) conditions. An important limitation of this cPCR assay was its inability to discriminate between active and inactive cells. This is an essential consideration for kinetic studies.
View details for DOI 10.1128/AEM.69.2.953-959.2003
View details for Web of Science ID 000180927100030
View details for PubMedID 12571017
View details for PubMedCentralID PMC143607
- Chemistry for Environmental Engineering and Science McGraw-Hill Inc.. 2003
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Comparison between donor substrates for biologically enhanced tetrachloroethene DNAPL dissolution
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2002; 36 (15): 3400-3404
Abstract
Tetrachloroethene (PCE) dense nonaqueous-phase liquid (DNAPL) can act as a persistent groundwater contamination source for decades. Biologically enhanced dissolution of pure PCE DNAPL has potential for reducing DNAPL longevity as indicated previously (Environ. Sci. Technol. 2000, 34, 2979). Reported here are expanded studies to evaluate donor substrates that offer different remediation strategies for bioenhanced DNAPL dissolution, including pentanol (soluble substrate, fed continuously), calcium oleate (insoluble substrate, placed in column initially by alternate pumping of sodium oleate and calcium chloride), and olive oil (mixed with PCE and placed in column initially). Compared with a no-substrate column control, the DNAPL dissolution rate was enhanced about three times when directly coupled with biological transformation. The major degradation product formed was cDCE, but significant amounts of VC and ethene were also found with some columns. Extensive methanogenesis, which reduced PCE transformation, occurred in both the pentanol-fed and oleate-amended columns, but not in the olive-oil-amended column, suggesting that methanogens managed to colonize column niches where PCE DNAPL was not present. Detrimental methane production in the pentanol-fed column was nearly eliminated by presaturating the feed solution with PCE. These results suggest potential DNAPL remediation strategies to enhance dehalogenation while controlling competitive methanogenic utilization of donor substrates.
View details for DOI 10.1021/es011408e
View details for Web of Science ID 000177242600049
View details for PubMedID 12188371
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Full-scale demonstration of in situ cometabolic biodegradation of trichloroethylene in groundwater - 2. Comprehensive analysis of field data using reactive transport modeling
WATER RESOURCES RESEARCH
2002; 38 (4)
View details for DOI 10.1029/2001WR000380
View details for Web of Science ID 000178932200003
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Strategies for in situ bioremediation of chlorinated solvent contaminated groundwater
3rd International Conference on Groundwater Quality
INT ASSOC HYDROLOGICAL SCIENCES. 2002: 319–24
View details for Web of Science ID 000185215100048
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Natural attenuation
Conference of the NATO-Advanced-Study-Institute on Innovative Approaches to the On-Site Assessment and Remediation of Contaminated Sites
SPRINGER. 2002: 141–181
View details for Web of Science ID 000180120800005
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Simulations of two-dimensional modeling of biomass aggregate growth in network models
WATER RESOURCES RESEARCH
2001; 37 (12): 2981-2994
View details for Web of Science ID 000173283000011
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Pore-scale modeling of biological clogging due to aggregate expansion: A material mechanics approach
WATER RESOURCES RESEARCH
2001; 37 (12): 2965-2979
View details for Web of Science ID 000173283000010
- Environmental Biotechnology, Principles and Applications McGraw-Hill Inc.. 2001
- The Development of Anaerobic Treatment and Its Future Water Science and Technolog 2001; 44 (8): 149-156
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Biologically enhanced dissolution of tetrachloroethene DNAPL
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2000; 34 (14): 2979-2984
View details for Web of Science ID 000088156100016
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Impact of colony morphologies and disinfection on biological clogging in porous media
ENVIRONMENTAL SCIENCE & TECHNOLOGY
2000; 34 (8): 1513-1520
View details for Web of Science ID 000086456100022
- Biomass, Oleate, and Other Possible Substrates for Chloroethene Reductive Dehalogenation Bioremediation Journal 2000; 4 (2): 125-133
- Bioremediation of Chlorinated Solvents in Groundwater Groundwater Contamination and Its Control in China edited by Fu, R., Qian, Y., Shoemaker, C. A. Tsinghua University Press. 2000: 83–94
- Novel Biological Removal of Hazardous Chemicals at Trace Levels Water Science and Technology 2000; 42 (12): 49-60
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Mass-transfer limitations for macroscale bioremediation modeling and implications on aquifer clogging
GROUND WATER
1999; 37 (4): 523-531
View details for Web of Science ID 000081268800012
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Effects of shear detachment on biomass growth and in situ bioremediation
GROUND WATER
1999; 37 (4): 555-563
View details for Web of Science ID 000081268800016
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Response to "Comment on 'Competition for hydrogen within a chlorinated solvent dehalogenating anaerobic mixed culture'"
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1999; 33 (12): 2128-2128
View details for Web of Science ID 000080965800029
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Mesoscale and microscale observations of biological growth in a silicon pore imaging element
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1999; 33 (8): 1230-1236
View details for Web of Science ID 000079974600014
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Chlorinated ethene half-velocity coefficients (K-s) for reductive dehalogenation
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1999; 33 (2): 223-226
View details for Web of Science ID 000078213600003
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Chlorinated Organics
Environmental Availability of Chlorinated Organics, Explosives, and Metals in Soils
edited by Anderson, W. C., Loehr, R. C., Smithi, B. P.
American Academy of Environmental Engineers. 1999: 35–84
View details for DOI 4
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Competition for hydrogen within a chlorinated solvent dehalogenating anaerobic mixed culture
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1998; 32 (22): 3591-3597
View details for Web of Science ID 000076986800022
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Spreadsheet method for evaluation of biochemical reaction rate coefficients and their uncertainties by weighted nonlinear least-squares analysis of the integrated monod equation
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1998; 64 (6): 2044-2050
View details for Web of Science ID 000073904800009
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Design of an in-situ injection/extraction bioremediation system
1st International Conference on Remediation of Chlorinated and Recalcitrant Compounds
BATTELLE PRESS. 1998: 33–38
View details for Web of Science ID 000075849600006
- Technology Transfer of an Innovative Remediation Technology from the Laboratory to the Field: A Case Study of In Situ Aerobic Cometabolic Bioremediation Environmental Engineering and Polic 1998; 1: 117-124
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Full scale evaluation of in situ cometabolic degradation of trichloroethylene in groundwater through toluene injection
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1998; 32 (1): 88-100
View details for Web of Science ID 000071284200035
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In vitro studies on reductive vinyl chloride dehalogenation by an anaerobic mixed culture
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1997; 63 (11): 4139-4144
Abstract
Reductive dehalogenation of vinyl chloride (VC) was studied in an anaerobic mixed bacterial culture. In growth experiments, ethene formation from VC increased exponentially at a rate of about 0.019 h(sup-1). Reductive VC dehalogenation was measured in vitro by using cell extracts of the mixed culture. The apparent K(infm) for VC was determined to be about 76 (mu)M; the V(infmax) was about 28 nmol (middot) min(sup-1) (middot) mg of protein(sup-1). The VC-dehalogenating activity was membrane associated. Propyl iodide had an inhibitory effect on the VC-dehalogenating activity in the in vitro assay. However, this inhibition could not be reversed by illumination. Cell extracts also catalyzed the reductive dehalogenation of cis-1,2-dichloroethene (cis-DCE) and, at a lower rate, of trichloroethene (TCE). Tetrachloroethene (PCE) was not transformed. The results indicate that the reductive dehalogenation of VC and cis-DCE described here is different from previously reported reductive dehalogenation of PCE and TCE.
View details for Web of Science ID A1997YE28100001
View details for PubMedID 16535722
View details for PubMedCentralID PMC1389278
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Development and evaluation of semicontinuous slurry microcosms to simulate in situ biodegradation of trichloroethylene in contaminated aquifers
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1997; 31 (10): 2915-2922
View details for Web of Science ID A1997XZ78700055
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Laboratory evaluation of a two-stage treatment system for TCE cometabolism by a methane-oxidizing mixed culture
BIOTECHNOLOGY AND BIOENGINEERING
1997; 55 (4): 650-659
Abstract
The objective of this research was to evaluate several factors affecting the performance of a two-stage treatment system employing methane-oxidizing bacteria for trichloroethylene (TCE) biodegradation. The system consists of a completely mixed growth reactor and a plug-flow transformation reactor in which the TCE is cometabolized. Laboratory studies were conducted with continuous growth reactors and batch experiments simulating transformation reactor conditions. Performance was characterized in terms of TCE transformation capacity (T(C), g TCE/g cells), transformation yield (T(Y), g TCE/g CH(4)), and the rate coefficient ratio k(TCE)/K(S,TCE) (L/mg-d). The growth reactor variables studied were solids retention time (SRT) and nutrient nitrogen (N) concentration. Formate and methane were evaluated as potential transformation reactor amendments. Comparison of cultures from 2- and 8-day SRT (nitrogen-limited) growth reactors indicated that there was no significant effect of growth reactor SRT or nitrogen availability on T(C) or T(Y), but N-limited conditions yielded higher k(TCE)/K(S,TCE). The TCE cometabolic activity of the 8-day SRT, N-limited growth reactor culture varied significantly during a 7-year period of operation. The T(C) and T(Y) of the resting cells increased gradually to levels a factor of 2 higher than the initial values. The reasons for this increase are unknown. Formate addition to the transformation reactor gave higher T(C) and T(Y) for 2-day SRT growth reactor conditions and significantly lower T(C), T(Y), and k(TCE)/K(S,TCE) for 8-day SRT N-limited conditions. Methane addition to the transformation reactor inhibited TCE cometabolism at low TCE concentrations and enhanced TCE cometabolism at high TCE concentrations, indicating that the TCE cometabolism in the presence of methane does not follow simple competitive inhibition kinetics. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 650-659, 1997.
View details for Web of Science ID A1997XM21300007
View details for PubMedID 18636575
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Effect of chlorinated ethenes on S-min for a methanotrophic mixed culture
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1997; 31 (8): 2204-2210
View details for Web of Science ID A1997XN75800034
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A novel means to develop strain-specific DNA probes for detecting bacteria in the environment
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1997; 63 (7): 2863-2869
Abstract
A simple means to develop strain-specific DNA probes for use in monitoring the movement and survival of bacteria in natural and laboratory ecosystems was developed. The method employed amplification of genomic DNA via repetitive sequence-based PCR (rep-PCR) using primers specific for repetitive extragenic palindromic (REP) elements, followed by cloning of the amplified fragments. The cloned fragments were screened to identify those which were strain specific, and these were used as probes for total genomic DNA isolated from microbial communities and subjected to rep-PCR. To evaluate the utility of the approach, we developed probes specific for Burkholderia cepacia G4 and used them to determine the persistence of the strain in aquifer sediment microcosms following bioaugmentation. Two of four probes tested were found to specifically hybridize to DNA fragments of the expected sizes in the rep-PCR fingerprint of B. cepacia G4 but not to 64 genetically distinct bacteria previously isolated from the aquifer. One of these probes, a 650-bp fragment, produced a hybridization signal when as few as 10 CFU of B. cepacia G4 were present in a mixture with 10(6) CFU nontarget strains, indicating that the sensitivity of these probes was comparable to those of other PCR-based detection methods. The probes were used to discriminate groundwater and microcosm samples that contained B. cepacia G4 from those which did not. False-positive results were obtained with a few samples, but these were readily identified by using hybridization to the second probe as a confirmation step. The general applicability of the method was demonstrated by constructing probes specific to three other environmental isolates.
View details for Web of Science ID A1997XJ18200055
View details for PubMedID 9212434
View details for PubMedCentralID PMC168583
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Breathing with chlorinated solvents.
Science
1997; 276 (5318): 1521-1522
View details for PubMedID 9190688
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Microbial succession during a field evaluation of phenol and toluene as the primary substrates for trichloroethene cometabolism
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1997; 63 (4): 1515-1522
Abstract
Microbial community composition and succession were studied in an aquifer that was amended with phenol, toluene, and chlorinated aliphatic hydrocarbons to evaluate the effectiveness of these aromatic substrates for stimulating trichloroethene (TCE) bioremediation. Samples were taken after the previous year's field studies, which used phenol as the primary substrate, and after three successive monthly treatments of phenol plus 1,1-dichloroethene (1,1-DCE) plus TCE, phenol plus TCE, and toluene plus TCE. Dominant eubacteria in the community were assessed after each of the four treatments by characterizing isolates from the most dilute most-probable-number tubes and by extracting DNA from aquifer samples. The succession of dominant phenol- and toluene-degrading strains was evaluated by genomic fingerprinting, cellular fatty acid methyl ester (FAME) analysis, and amplified ribosomal DNA restriction analysis (ARDRA). 1,1-DCE was found to drastically reduce microbial growth and species richness, which corresponded to the reduction in bioremediation effectiveness noted previously for this treatment (G. D. Hopkins and P. L. McCarty, Environ. Sci. Technol. 29:1628-1637, 1995). Only a few gram-positive isolates could be obtained after treatment with 1,1-DCE, and these were not seen after any other treatments. Microbial densities returned to their original levels following the subsequent phenol-TCE treatment, but the original species richness was not restored until after the subsequent toluene-TCE treatment. Genomic fingerprinting and FAME analysis indicated that six of the seven originally dominant microbial groups were still dominant after the last treatment, indicating that the community is quite resilient to toxic disturbance by 1,1-DCE. FAME analysis indicated that six microbial taxa were dominant: three members of the (beta) subclass of the class Proteobacteria (Comamonas-Variovorax, Azoarcus, and Burkholderia) and three gram-positive groups (Bacillus, Nocardia, and an unidentified group). ARDRA revealed that the dominant community members were stable during the three nontoxic treatments and that virtually all of the bands could be accounted for by isolates from five of the dominant taxa, indicating that the isolation protocol used likely recovered most of the dominant members of this community.
View details for Web of Science ID A1997WR16200048
View details for PubMedID 16535576
View details for PubMedCentralID PMC1389554
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Long-term biodegradation of trichloroethylene influenced by bioaugmentation and dissolved oxygen in aquifer microcosms
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1997; 31 (3): 786-791
View details for Web of Science ID A1997WK81500052
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Numerical modeling and uncertainties in rate coefficients for methane utilization and TCE cometabolism by a methane-oxidizing mixed culture
BIOTECHNOLOGY AND BIOENGINEERING
1997; 53 (3): 320-331
Abstract
The rates of methane utilization and trichloroethylene (TCE) cometabolism by a methanotrophic mixed culture were characterized in batch and pseudo-steady-state studies. Procedures for determination of the rate coefficients and their uncertainties by fitting a numerical model to experimental data are described. The model consisted of a system of differential equations for the rates of Monod kinetics, cell growth on methane and inactivation due to TCE transformation product toxicity, gas/liquid mass transfer of methane and TCE, and the rate of passive losses of TCE. The maximum specific rate of methane utilization (k(CH(4) )) was determined by fitting the numerical model to batch experimental data, with the initial concentration of active methane-oxidizing cells (X(0) (a)) also used as a model fitting parameter. The best estimate of k(CH(4) ) was 2.2 g CH(4)/g cells-d with excess copper available, with a single-parameter 95% confidence interval of 2.0-2.4 mg/mg-d. The joint 95% confidence region for k(CH(4) ) and X(0) (a) is presented graphically. The half-velocity coefficient (K(S,CH(4) )) was 0.07 mg CH(4)/L with excess copper available and 0.47 mg CH(4)/L under copper limitation, with 95% confidence intervals of 0.02-0.11 and 0.35-0.59 mg/L, respectively. Unique values of the TCE rate coefficients k(TCE) and K(S,TCE) could not be determined because they were found to be highly correlated in the model fitting analysis. However, the ratio k(TCE)/K(S,TCE) and the TCE transformation capacity (T(C)) were well defined, with values of 0.35 L/mg-day and 0.21 g TCE/g active cells, respectively, for cells transforming TCE in the absence of methane or supplemental formate. The single-parameter 95% confidence intervals for k(TCE)/K(S,TCE) and T(C) were 0.27-0.43 L/mg-d and 0.18-0.24 g TCE/g active cells, respectively. The joint 95% confidence regions for k(TCE)/K(S,TCE) and T(C) are presented graphically.
View details for Web of Science ID A1997WG06900011
View details for PubMedID 18633987
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Transformation yields of chlorinated ethenes by a methanotrophic mixed culture expressing particulate methane monooxygenase
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1997; 63 (2): 687-693
Abstract
Transformation yields for the aerobic cometabolic degradation of five chlorinated ethenes were determined by using a methanotrophic mixed culture expressing particulate methane monooxygenase (pMMO). Transformation yields (expressed as moles of chlorinated ethene degraded per mole of methane consumed) were 0.57, 0.25, 0.058, 0.0019, and 0.00022 for trans-1,2-dichloroethylene (t-DCE), vinyl chloride (VC), cis-1,2-dichloroethylene (c-DCE), trichloroethylene (TCE), and 1,1-dichloroethylene (1,1-DCE), respectively. Degradation of t-DCE and VC was observed only in the presence of formate or methane, sources of reducing energy necessary for cometabolism. The t-DCE and VC transformation yields represented 35 and 15%, respectively, of the theoretical maximum yields, based on reducing-energy availability from methane dissimilation to carbon dioxide, exclusive of all other processes that require reducing energy. The yields for t-DCE and VC were 20 times greater than the yields reported by others for cells expressing soluble methane monooxygenase (sMMO). Transformation yields for c-DCE, TCE, and 1,1-DCE were similar to or less than those for cultures expressing sMMO. Although methanotrophic biotreatment systems have typically been designed to incorporate cultures expressing sMMO, these results suggest that pMMO expression may be highly advantageous for degradation of t-DCE or VC. It may also be much easier to maintain pMMO expression in treatment systems, because pMMO is expressed by all methanotrophs whereas sMMO is expressed only by type II methanotrophs under copper-limited conditions.
View details for Web of Science ID A1997WF49600050
View details for PubMedID 9023946
View details for PubMedCentralID PMC168358
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The environmental engineering and science program at Stanford University
1996 Environmental Engineering Education Conference on the Relationship to Engineering Practice
AMERICAN ACADEMY ENVIRONMENTAL ENGINEERS. 1997: 51–53
View details for Web of Science ID A1997BJ39E00009
- Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons Subsurface Restoration edited by Ward, C. H., Cherry, J. A., Scalf, M. R. Ann Arbor Press, Inc.. 1997: 373–395
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Bioaugmentation with Burkholderia cepacia: Trichloroethylene cometabolism vs. colonization
4th International In Situ and On-Site Bioremediation Symposium
BATTELLE PRESS. 1997: 501–506
View details for Web of Science ID A1997BH89V00112
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Effect of three chlorinated ethenes on growth rates for a methanotrophic mixed culture
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1996; 30 (12): 3517-3524
View details for Web of Science ID A1996VV20500039
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Enhancement of trichloroethylene degradation in aquifer microcosms bioaugmented with wild type and genetically altered Burkholderia (Pseudomonas) cepacia G4 and PR1
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1996; 30 (6): 2045-2052
View details for Web of Science ID A1996UM99100056
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Isolation and characterization of a facultatively aerobic bacterium that reductively dehalogenates tetrachloroethene to cis-1,2-dichloroethene
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1996; 62 (3): 761-765
Abstract
A rapidly-growing facultatively aerobic bacterium that transforms tetrachloroethene (PCE) via trichloroethene (TCE) to cis-1,2-dichloroethene (cis-1,2-DCE) at high rates in a defined medium was isolated from a contaminated site. Metabolic characterization, cellular fatty acid analysis, and partial sequence analysis of 16S rRNA showed that the new isolate, strain MS-1, has characteristics matching those of the members of the family Enterobacteriaceae. Strain MS-1 can oxidize about 58 substrates including many carbohydrates, short-chain fatty acids, amino acids, purines, and pyrimidines. It can transform up to 1 mM PCE (aqueous) at a rate of about 0.5 (mu)mol of PCE(middot) h(sup-1)(middot)mg (dry weight) of cell(sup-1). PCE transformation occurs following growth on or with the addition of single carbon sources such as glucose, pyruvate, formate, lactate, or acetate or with complex nutrient sources such as yeast extract or a mixture of amino acids. PCE dehalogenation requires the absence of oxygen, nitrate, and high concentrations of fermentable compounds such as glucose. Enterobacter agglomerans biogroup 5 (ATCC 27993), a known facultative bacterium that is closely related to strain MS-1, also reductively dehalogenated PCE to cis-1,2-DCE. To our knowledge, this is the first report on isolation of a facultative bacterium that can reductively transform PCE to cis-1,2-DCE under defined physiological conditions. Also, this is the first report of the ability of E. agglomerans to dehalogenate PCE.
View details for Web of Science ID A1996TY36500003
View details for PubMedID 16535267
View details for PubMedCentralID PMC1388792
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Transferability of biotreatment from site to site
OECD Workshop Amsterdam 95 on Wider Application and Diffusion of Bioremediation Technologies
ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT. 1996: 201–210
View details for Web of Science ID A1996BG53M00020
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METHANOTROPHIC CHLOROETHENE TRANSFORMATION CAPACITIES AND 1,1-DICHLOROETHENE TRANSFORMATION PRODUCT TOXICITY
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1995; 29 (11): 2741-2747
View details for Web of Science ID A1995TC85600025
View details for PubMedID 22206519
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APPARATUS FOR DOWN-WELL OXYGEN-TRANSFER INTO CONTAMINATED AQUIFERS
JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE
1995; 121 (8): 565-570
View details for Web of Science ID A1995RK48500004
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SMALL COLUMN MICROCOSM FOR ASSESSING METHANE-STIMULATED VINYL-CHLORIDE TRANSFORMATION IN AQUIFER SAMPLES
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1995; 29 (8): 1892-1897
View details for Web of Science ID A1995RL82900027
View details for PubMedID 22191334
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FIELD-EVALUATION OF IN-SITU AEROBIC COMETABOLISM OF TRICHLOROETHYLENE AND 3 DICHLOROETHYLENE ISOMERS USING PHENOL AND TOLUENE AS THE PRIMARY SUBSTRATES
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1995; 29 (6): 1628-1637
View details for Web of Science ID A1995RB13100046
View details for PubMedID 22276888
- Field Studies: Elicitation of Fate and Transport Processes and Application of Full-Scale Remediation Soil and Groundwater Pollution edited by Zehnder, A. J. Klluwer Academic Publishers. 1995: 110–116
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MODEL FOR TREATMENT OF TRICHLOROETHYLENE BY METHANOTROPHIC BIOFILMS
JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE
1994; 120 (2): 379-400
View details for Web of Science ID A1994NC98700008
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FACTORS AFFECTING TRANSFORMATION OF CHLORINATED ALIPHATIC HYDROCARBONS BY METHANOTROPHS
2nd International Symposium on In Situ and On-Site Bioreclamation
LEWIS PUBLISHERS INC. 1994: 303–308
View details for Web of Science ID A1994BC30T00030
- A Laboratory and Field Evaluation of Enhanced In-Situ Bioremediation of Trichloroethylene, cis- and trans-Dichloroethylene, and Vinyl Chloride by Methanotrophic Bacteria Bioremediation Field Experienc edited by Flathman, P. E., Ferger, D. E., Exner, J. H. Lewis Publishers. 1994: 383–412
- Ground-Water Treatment for Chlorinated Solvents Handbook of Bioremediation edited by Norris, R. D. Lewis Publishers. 1994: 87–116
- Chemistry for Environmental Engineering McGraw-Hill Inc.. 1994
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A FIELD AND MODELING COMPARISON OF INSITU TRANSFORMATION OF TRICHLOROETHYLENE BY METHANE UTILIZERS AND PHENOL UTILIZERS
2nd International Symposium on In Situ and On-Site Bioreclamation
LEWIS PUBLISHERS INC. 1994: 248–254
View details for Web of Science ID A1994BC30T00021
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VARIATION OF CARBON-MONOXIDE PRODUCTION DURING METHANE FERMENTATION OF GLUCOSE
WATER ENVIRONMENT RESEARCH
1993; 65 (7): 890-898
View details for Web of Science ID A1993MK51100011
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TRICHLOROETHYLENE CONCENTRATION EFFECTS ON PILOT FIELD-SCALE IN-SITU GROUNDWATER BIOREMEDIATION BY PHENOL-OXIDIZING MICROORGANISMS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1993; 27 (12): 2542-2547
View details for Web of Science ID A1993ME57800049
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SORPTION OF TRICHLOROETHYLENE ONTO A ZEOLITE ACCOMPANIED BY METHANOTROPHIC BIOTRANSFORMATION
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1993; 27 (10): 2141-2148
View details for Web of Science ID A1993LZ74900028
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MICROCOSM AND IN-SITU FIELD STUDIES OF ENHANCED BIOTRANSFORMATION OF TRICHLOROETHYLENE BY PHENOL-UTILIZING MICROORGANISMS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1993; 59 (7): 2277-2285
Abstract
The ability of different aerobic groundwater microorganisms to cometabolically degrade trichloroethylene (TCE), 1,2-cis-dichloroethylene (c-DCE), and 1,2-trans-dichloroethylene (t-DCE) was evaluated both in groundwater-fed microcosms and in situ in a shallow aquifer. Microcosms amended with phenol or toulene were equally effective in removing c-DCE (> 90%) followed by TCE (60 to 70%), while the microcosm fed methane was most effective in removing t-DCE (> 90%). The microcosm fed ammonia was the least effective. None of the microcosms effectively degraded 1,1,1-trichloroethane. At the Moffett Field groundwater test site, in situ removal of c-DCE and TCE coincided with biostimulation through phenol and oxygen injection and utilization, with c-DCE removed more rapidly than TCE. Greater TCE and c-DCE removal was observed when the phenol concentration was increased. Over 90% removal of c-DCE and TCE was observed in the 2-m biostimulated zone. This compares with 40 to 50% removal of c-DCE and 15 to 25% removal of TCE achieved by methane-grown microorganisms previously evaluated in an adjacent in situ test zone. The in situ removal with phenol-grown microorganisms agrees qualitatively with the microcosm studies, with the rates and extents of removal ranked as follows: c-DCE > TCE > t-DCE. These studies demonstrate the potential for in situ TCE bioremediation using microorganisms grown on phenol.
View details for Web of Science ID A1993LL31000043
View details for PubMedID 8357259
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INFLUENCE OF THE ENDOGENOUS STORAGE LIPID POLY-BETA-HYDROXYBUTYRATE ON THE REDUCING POWER-AVAILABILITY DURING COMETABOLISM OF TRICHLOROETHYLENE AND NAPHTHALENE BY RESTING METHANOTROPHIC MIXED CULTURES
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1993; 59 (5): 1602-1606
Abstract
The role of the storage lipid poly-beta-hydroxybutyrate (PHB) in trichloroethylene transformation by methanotrophic mixed cultures was investigated. Naphthalene oxidation rates were used to assay for soluble methane monooxygenase activity. The PHB content of methanotrophic cells grown in reactors varied diurnally as well as from day to day. A positive correlation between the amount of PHB in the cells and the naphthalene oxidation rate as well as between PHB and the trichloroethylene transformation rate and capacity was found. Addition of beta-hydroxybutyrate increased the naphthalene oxidation rates significantly. PHB content in cells could be manipulated by incubation at different methane-to-nitrogen ratios. A positive correlation between the naphthalene oxidation rate and the PHB content after these incubations could be seen. Both the PHB content and the naphthalene oxidation rates decreased with time in resting methanotrophic cells exposed to oxygen. However, this decrease in the naphthalene oxidation rate cannot be explained by the decrease in the PHB content alone. Probably a deactivation of the methane monooxygenase itself is also involved.
View details for Web of Science ID A1993LA78000052
View details for PubMedID 16348940
View details for PubMedCentralID PMC182125
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INHIBITION OF BUTYRATE OXIDATION BY FORMATE DURING METHANOGENESIS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1993; 59 (2): 628-630
Abstract
A mixed methanogenic culture fed with glucose was perturbed with butyrate and formate to investigate the role of formate in the acetogenesis of butyrate. A free energy analysis suggests that formate rather than H(2) was the interspecies electron carrier for butyrate conversion into acetate for the culture studied.
View details for Web of Science ID A1993KK91600047
View details for PubMedID 16348880
View details for PubMedCentralID PMC202158
- In Situ Bioremediation of Chlorinated Solvents Current Opinion in Biotechnology 1993; 4 (3): 103-115
- Biological and Chemical Transformations of Halogenated Aliphatic Compounds in Aquatic and Terrestrial Environments Biogeochemistry of Global Change: Radiatively Active Trace Gases edited by Oremland, R. S. Chapman & Hall, Inc.. 1993: 839–852
- Engineering and Hydrogeological Problems Associated with In Situ Treatment Hydrological Sciences 1993; 38 (4): 261-272
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INSITU TRANSFORMATION OF CARBON-TETRACHLORIDE AND OTHER HALOGENATED COMPOUNDS RESULTING FROM BIOSTIMULATION UNDER ANOXIC CONDITIONS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1992; 26 (12): 2454-2461
View details for Web of Science ID A1992KA32800025
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CHARACTERIZATION OF A METHANE-UTILIZING BACTERIUM FROM A BACTERIAL CONSORTIUM THAT RAPIDLY DEGRADES TRICHLOROETHYLENE AND CHLOROFORM
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1992; 58 (6): 1886-1893
Abstract
A mixed culture of bacteria grown in a bioreactor with methane as a carbon and energy source rapidly oxidized trichloroethylene and chloroform. The most abundant organism was a crescent-shaped bacterium that bound the fluorescent oligonucleotide signature probes that specifically hybridize to serine pathway methylotrophs. The 5S rRNA from this bacterium was found to be 93.5% homologous to the Methylosinus trichosporium OB3b 5S RNA sequence. A type II methanotrophic bacterium, isolated in pure culture from the bioreactor, synthesized soluble methane monooxygenase during growth in a copper-limited medium and was also capable of rapid trichloroethylene oxidation. The bacterium contained the gene that encodes the soluble methane monooxygenase B component on an AseI restriction fragment identical in size to a restriction fragment present in AseI digests of DNA from bacteria in the mixed culture. The sequence of the 16S rRNA from the pure culture was found to be 92 and 94% homologous to the 16S rRNAs of M. trichosporium OB3b and M. sporium, respectively. Both the pure and mixed cultures oxidized naphthalene to naphthol, indicating the presence of soluble methane monooxygenase. The mixed culture also synthesized soluble methane monooxygenase, as evidenced by the presence of proteins that cross-reacted with antibodies prepared against purified soluble methane monooxygenase components from M. trichosporium OB3b on Western blots (immunoblots). It was concluded that a type II methanotrophic bacterium phylogenetically related to Methylosinus species synthesizes soluble methane monooxygenase and is responsible for trichloroethylene oxidation in the bioreactor.
View details for Web of Science ID A1992HX94500015
View details for PubMedID 1377902
- Movement and Transformations of Halogenated Aliphatic Compounds in Natural Systems Fate of Pesticides and Chemicals in the Environment edited by Schnoor, J. L. John Wiley I& Sons, Inc.. 1992: 191–209
- Pilot Scale Field Studies of In-Situ Bioremediation of Chlorinated Solvents Journal of Hazardous Materials 1992; 32: 145-162
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COMPARISON BETWEEN MODEL SIMULATIONS AND FIELD RESULTS FOR INSITU BIORESTORATION OF CHLORINATED ALIPHATICS .2. COMETABOLIC TRANSFORMATIONS
GROUND WATER
1992; 30 (1): 37-44
View details for Web of Science ID A1992GX62600006
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A COMETABOLIC BIOTRANSFORMATION MODEL FOR HALOGENATED ALIPHATIC-COMPOUNDS EXHIBITING PRODUCT TOXICITY
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1991; 25 (8): 1381-1387
View details for Web of Science ID A1991FY99800009
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2-STAGE DISPERSED-GROWTH TREATMENT OF HALOGENATED ALIPHATIC-COMPOUNDS BY COMETABOLISM
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1991; 25 (8): 1387-1393
View details for Web of Science ID A1991FY99800010
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ELECTROLYTIC MODEL SYSTEM FOR REDUCTIVE DEHALOGENATION IN AQUEOUS ENVIRONMENTS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1991; 25 (5): 973-978
View details for Web of Science ID A1991FK08300028
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COMPARISON BETWEEN MODEL SIMULATIONS AND FIELD RESULTS FOR INSITU BIORESTORATION OF CHLORINATED ALIPHATICS .1. BIOSTIMULATION OF METHANOTROPHIC BACTERIA
GROUND WATER
1991; 29 (3): 365-374
View details for Web of Science ID A1991FJ70000006
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PRODUCT TOXICITY AND COMETABOLIC COMPETITIVE-INHIBITION MODELING OF CHLOROFORM AND TRICHLOROETHYLENE TRANSFORMATION BY METHANOTROPHIC RESTING CELLS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1991; 57 (4): 1031-1037
Abstract
The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured. As reported previously for TCE, formate addition resulted in an increased CF transformation rate (0.35 day-1 for resting cells and 1.5 day-1 for formate-fed cells) and transformation capacity (0.0065 mg of CF per mg of cells for resting cells and 0.015 mg of CF per mg of cells for formate-fed cells), suggesting that depletion of energy stores affects transformation behavior. The observed finite transformation capacity, even with an exogenous energy source, suggests that toxicity was also a factor. CF transformation capacity was significantly lower than that for TCE, suggesting a greater toxicity from CF transformation. The toxicity of CF, TCE, and their transformation products to whole cells was evaluated by comparing the formate oxidation activity of acetylene-treated cells to that of non-acetylene-treated cells with and without prior exposure to CF or TCE. Acetylene arrests the activity of methane monooxygenase in CF and TCE oxidation without halting cell activity toward formate. Significantly diminished formate oxidation by cells exposed to either CR or TCE without acetylene compared with that with acetylene suggests that the solvents themselves were not toxic under the experimental conditions but their transformation products were. The concurrent transformation of CF and TCE by resting cells was measured, and results were compared with predictions from a competitive-inhibition cometabolic transformation model. The reasonable fit between model predictions and experimental observations was supportive of model assumptions.
View details for Web of Science ID A1991FF03900023
View details for PubMedID 1905516
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A FIELD-EVALUATION OF INSITU BIODEGRADATION OF CHLORINATED ETHENES .3. STUDIES OF COMPETITIVE-INHIBITION
GROUND WATER
1991; 29 (2): 239-250
View details for Web of Science ID A1991FA88300012
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INSITU BIOTRANSFORMATION OF CARBON-TETRACHLORIDE, FREON-113, FREON-11, AND 1,1,1-TCA UNDER ANOXIC CONDITIONS
INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION
BUTTERWORTH-HEINEMANN. 1991: 41–58
View details for Web of Science ID A1991BU85J00003
- Terrestrial Physical and Chemical Processes for Liquid Waste Treatment Waste Management & Research 1991; 9: 379-387
- Engineering Concepts for In Situ Bioremediation Journal of Hazardous Materials 1991; 28: 1-11
- Microbial Processes in Porous Media," Transport Processes in Porous Media Transport Processes in Porous Media edited by Bear, J., Corapcioglu, M. Y. Kluwer Academic Publishers. 1991: 639–691
- Modeling of Anaerobic Digestion Processes (A Discussion of Concepts) Water Science and Technology 1991; 24 (8): 17-33
- Microbial Hydrolysis of Lignocellulosic Materials Methane from Community Wastes edited by Isaacson, R. Elsevier Publishers. 1991: 61–100
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EFFECTS OF TOXICITY, AERATION, AND REDUCTANT SUPPLY ON TRICHLOROETHYLENE TRANSFORMATION BY A MIXED METHANOTROPHIC CULTURE
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1991; 57 (1): 228-235
Abstract
The trichloroethylene (TCE) transformation rate and capacity of a mixed methanotrophic culture at room temperature were measured to determine the effects of time without methane (resting), use of an alternative energy source (formate), aeration, and toxicity of TCE and its transformation products. The initial specific TCE transformation rate of resting cells was 0.6 mg of TCE per mg of cells per day, and they had a finite TCE transformation capacity of 0.036 mg of TCE per mg of cells. Formate addition resulted in increased initial specific TCE transformation rates (2.1 mg/mg of cells per day) and elevated transformation capacity (0.073 mg of TCE per mg of cells). Significant declines in methane conversion rates following exposure to TCE were observed for both resting and formate-fed cells, suggesting toxic effects caused by TCE or its transformation products. TCE transformation and methane consumption rates of resting cells decreased with time much more rapidly when cells were shaken and aerated than when they remained dormant, suggesting that the transformation ability of methanotrophs is best preserved by storage under anoxic conditions.
View details for Web of Science ID A1991ER20600035
View details for PubMedID 2036009
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DEGRADATION OF TOLUENE AND PARA-XYLENE IN ANAEROBIC MICROCOSMS - EVIDENCE FOR SULFATE AS A TERMINAL ELECTRON-ACCEPTOR
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
1991; 10 (11): 1379-1389
View details for Web of Science ID A1991GM68800002
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BIOTRANSFORMATION OF MONOAROMATIC HYDROCARBONS UNDER ANOXIC CONDITIONS
INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION
BUTTERWORTH-HEINEMANN. 1991: 458–463
View details for Web of Science ID A1991BU85H00030
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INSITU METHANOTROPHIC BIOREMEDIATION FOR CONTAMINATED GROUNDWATER AT ST-JOSEPH, MICHIGAN
INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION
BUTTERWORTH-HEINEMANN. 1991: 16–40
View details for Web of Science ID A1991BU85J00002
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TRANSFORMATION OF CARBON-TETRACHLORIDE BY PSEUDOMONAS SP STRAIN KC UNDER DENITRIFICATION CONDITIONS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1990; 56 (11): 3240-3246
Abstract
A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of 14C-labeled CT by Pseudomonas strain KC under denitrification conditions were 14CO2 and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging.
View details for Web of Science ID A1990EF66300002
View details for PubMedID 2268146
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COLUMN STUDIES ON METHANOTROPHIC DEGRADATION OF TRICHLOROETHENE AND 1,2-DICHLOROETHANE
GROUND WATER
1990; 28 (6): 910-919
View details for Web of Science ID A1990EG55900009
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REDUCTIVE DEHALOGENATION OF CARBON-TETRACHLORIDE BY ESCHERICHIA-COLI K-12
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1990; 56 (11): 3247-3254
Abstract
The formation of radicals from carbon tetrachloride (CT) is often invoked to explain the product distribution resulting from its transformation. Radicals formed by reduction of CT presumably react with constituents of the surrounding milieu to give the observed product distribution. The patterns of transformation observed in this work were consistent with such a hypothesis. In cultures of Escherichia coli K-12, the pathways and rates of CT transformation were dependent on the electron acceptor condition of the media. Use of oxygen and nitrate as electron acceptors generally prevented CT metabolism. At low oxygen levels (approximately 1%), however, transformation of [14C]CT to 14CO2 and attachment to cell material did occur, in accord with reports of CT fate in mammalian cell cultures. Under fumarate-respiring conditions, [14C]CT was recovered as 14CO2, chloroform, and a nonvolatile fraction. In contrast, fermenting conditions resulted in more chloroform, more cell-bound 14C, and almost no 14CO2. Rates of transformation of CT were faster under fermenting conditions than under fumarate-respiring conditions. Transformation rates also decreased over time, suggesting the gradual exhaustion of transformation activity. This loss was modeled with a simple exponential decay term.
View details for Web of Science ID A1990EF66300003
View details for PubMedID 2268147
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A FIELD-EVALUATION OF INSITU BIODEGRADATION OF CHLORINATED ETHENES .2. RESULTS OF BIOSTIMULATION AND BIOTRANSFORMATION EXPERIMENTS
GROUND WATER
1990; 28 (5): 715-727
View details for Web of Science ID A1990DY03900008
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METHANE FERMENTATION OF SELECTED LIGNOCELLULOSIC MATERIALS
BIOMASS
1990; 21 (4): 239-255
View details for Web of Science ID A1990CW95100001
- Scientific Limits to Remediation of Contaminated Soils and Groundwater Ground Water and Soil Contamination Remediation: Toward Compatible Science, Policy, and Public Perception National Academy Press. 1990: 38–52
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FACTORS GOVERNING METHANE FLUCTUATIONS FOLLOWING SHOCK LOADING OF DIGESTERS
RESEARCH JOURNAL OF THE WATER POLLUTION CONTROL FEDERATION
1990; 62 (1): 58-64
View details for Web of Science ID A1990CK43800008
- Volatile Organic Chemicals and Intentional Reuse Significance and Treatment of Volatile Organic Compounds in Water Supplies edited by Ram, N. M., Christman, R. F. Lewis Publishers, Inc.. 1990: 127–138
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REDUCED PRODUCT FORMATION FOLLOWING PERTURBATION OF ETHANOL-FED AND PROPIONATE-FED METHANOGENIC CSTRS
BIOTECHNOLOGY AND BIOENGINEERING
1989; 34 (7): 885-895
Abstract
Energetic analysis was applied to reduced product formation following perturbation of ethanol- and propionate-fed methanogenic continuous stirred tank reactors (CSTRs). Formation and dissipation of longer-chained n-carboxylic acids corresponded with the variation in Gibbs free energy change associated with beta-oxidation reactions. Formation appeared to occur from acetate and propionate by reductive back-reactions, made energetically favorable by elevated hydrogen partial pressure (P(H(2))), and possibly mediated by biosynthetic enzymes. The formed longer-chained acids dissipated when the P(H(2)) fell and equilibrium shifted to favor beta-oxidations. n-Propanol was found to be produced from propionate in a coupled ethanol oxidation/propionate reduction reaction, mediated by ethanol-oxidizing organisms during high rates of ethanol utilization and elevated P(H(2)). When P(H(2)) declined, n-propanol was oxidized back to its precursor propionate. Both reaction energetics and intracellular diffusion of the electron carrier may effect transient mediation of this coupled reaction.
View details for Web of Science ID A1989AQ78100001
View details for PubMedID 18588179
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BIOTRANSFORMATION OF HALOGENATED AND NONHALOGENATED OCTYLPHENOL POLYETHOXYLATE RESIDUES UNDER AEROBIC AND ANAEROBIC CONDITIONS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1989; 23 (8): 951-961
View details for Web of Science ID A1989AH87000011
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ENERGETIC AND RATE EFFECTS ON METHANOGENESIS OF ETHANOL AND PROPIONATE IN PERTURBED CSTRS
BIOTECHNOLOGY AND BIOENGINEERING
1989; 34 (1): 39-54
Abstract
Energetic and reaction-rate interactions between hydrogenic (hydrogen-producing) and hydrogenotrophic (hydrogen-consuming) bacteria were investigated in five perturbation experiments performed on steady-state, mixed-culture methanogenic CSTRs receiving ethanol, propionate, or both hydrogenic substrates. When a large quantity of propionate was suddenly added to a propionatefed CSTR, P(H(2) ) increased to 10(-4) atm and propionate oxidation remained energetically favorable. When ethanol was added to a CSTR receiving ethanol, P(H(2) ) rose to 6.3 x 10(-3) atm within 5 h. In both perturbations, P(H(2) ) remained at levels such that oxidation of the hydrogenic substrate remained energetically favorable throughout the transient. Sudden increase in ethanol concentration in the ethanol- and propionate-fed CSTR resulted in an increase in P(H(2) ) such that propionate oxidation became energetically unfavorable and was blocked. Propionate utilization resumed when the added ethanol was depleted and P(H(2) ) returned to its previous steady-state levels. Ethanol perturbation of ethanol- and propionate-fed CSTRs led to the formation of reduced products, including n-propanol and four-through seven-carbon n-carboxylic acids, when P(H(2) ) was elevated; these products disappeared after P(H(2) ) returned to previous, steady-state levels. The transformations were consistent with reaction energetics. Reduced product formation may have been a sink for reducing equivalents, as an alternative to oxidation for propionate utilization, as indicated by an electron equivalents balance over the time course of experiments.
View details for Web of Science ID A1989U763800005
View details for PubMedID 18588049
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KINETICS OF BIOTRANSFORMATION OF 1,1,1-TRICHLOROETHANE BY CLOSTRIDIUM SP STRAIN TCAIIB
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1989; 55 (4): 845-851
Abstract
Batch experiments were conducted to examine the effects of high concentrations of 1,1,1-trichloroethane (TCA) on the biotransformation of TCA by Clostridium sp. strain TCAIIB. The biotic dehalogenation of TCA to 1,1-dichloroethane by nongrowing cells was measured at 35 degrees C, and the data were used to obtain the kinetic parameters of the Monod relationship half-velocity coefficient Ks (31 microM) and the coefficient of maximum rate of TCA biotransformation (kTCA; 0.28 mumol per mg per day). The yield of biomass decreased with an increase in the TCA concentration, although TCA concentrations up to 750 microM did not completely inhibit bacterial growth. Also, kTCA was higher in the presence of high concentrations of TCA. A mathematical model based on a modified Monod equation was used to describe the biotransformation of TCA. The abiotic transformation of TCA to 1,1-dichloroethene was measured at 35 degrees C, and the first-order formation rate coefficient for 1,1-dichloroethene (ke) was determined to be 0.86 per year.
View details for Web of Science ID A1989T976100012
View details for PubMedID 2729986
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BIOTRANSFORMATION OF 1,1,1-TRICHLOROETHANE, TRICHLOROMETHANE, AND TETRACHLOROMETHANE BY A CLOSTRIDIUM SP
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1989; 55 (4): 837-844
Abstract
A gram-positive, strictly anaerobic, motile, endospore-forming rod, tentatively identified as a proteolytic Clostridium sp., was isolated from the effluent of an anaerobic suspended-growth bioreactor. The organism was able to biotransform 1,1,1-trichloroethane, trichloromethane, and tetrachloromethane. 1,1,1-Trichloroethane was completely transformed (greater than or equal to 99.5%) by reductive dehalogenation to 1,1-dichloroethane (30 to 40%) and, presumably by other mechanisms, to acetic acid (7%) and unidentified products. The reductive dehalogenation of tetrachloromethane led to the intermediate trichloromethane, which was further transformed to dichloromethane (8%) and unidentified products. The biotransformation occurred during the exponential growth phase, as well as during the stationary phase. Tetrachlorethene, trichloroethene, 1,1-dichloroethene, chloroethane, 1,1-dichloroethane, and dichloromethane were not biotransformed significantly by the organism.
View details for Web of Science ID A1989T976100011
View details for PubMedID 2729985
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DEGRADATION OF TRICHLOROETHYLENE BY METHANOTROPHIC BACTERIA IN A LABORATORY COLUMN OF SATURATED AQUIFER MATERIAL
WATER SCIENCE AND TECHNOLOGY
1988; 20 (11-12): 175-178
View details for Web of Science ID A1988T894100026
- Environmental Biotechnology, Reducing Risks from Environmental Chemicals through Biotechnology edited by Omenn, C. S., Colwell, R., Chakrabarty, A. M., Lewis, A. M., McCarty, P. L. Plenum Press. 1988
- Bioengineering Issues Related to In-Situ Remediation of Contaminated Soils and Groundwater Environmental Biotechnology edited by Omenn, G. S. Plenum Publishing Corp.. 1988: 143–162
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THERMOCHEMICAL PRETREATMENT OF LIGNOCELLULOSE TO ENHANCE METHANE FERMENTATION .1. MONOSACCHARIDE AND FURFURALS HYDROTHERMAL DECOMPOSITION AND PRODUCT FORMATION RATES
BIOTECHNOLOGY AND BIOENGINEERING
1988; 31 (1): 50-61
Abstract
Over a pH range 1-4 and temperatures from 170 to 230 degrees C, the decomposition rates of xylose, galactose, mannose, glucose, 2-furfural, and 5-hydroxymethyl-2-furfural (5-HMF) were pseudo first order. The effect of temperature and pH on the pseudo first-order decomposition rate constants was modeled using the Arrhenius equation and acid-base catalysis, respectively. Decomposition rates of the monosaccharides were minimum at a pH 2-2.5. Above pH 2.5, the monosaccharide decomposition was base catalyzed, with acid catalysis occurring at a pH of less than 2 for glucose. The furfurals were subject to acid catalysis at below ca. pH 3.5. The hydrothermal conversion of glucose to its decomposition products during thermochemical Pretreatment can be modeled as a combination of series and parallel reactions. The formation rates of identified soluble products from glucose decomposition, 5-HMF and levulinic acid, were also functions of temperature and pH. The rate of 5-HMF formation relative to glucose decomposition decreased as the pH increased from 2.0 to 4.0, with levulinic acid formation only detected when the pH was 2.5 or less. For glucose decomposition, humic solids accounted for ca. 20% of the decomposition products.
View details for Web of Science ID A1988L611800008
View details for PubMedID 18581563
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THERMOCHEMICAL PRETREATMENT OF LIGNOCELLULOSE TO ENHANCE METHANE FERMENTATION .2. EVALUATION AND APPLICATION OF PRETREATMENT MODEL
BIOTECHNOLOGY AND BIOENGINEERING
1988; 31 (1): 62-70
Abstract
A model was developed and evaluated as a tool for predicting the formation of soluble products from staged thermochemical treatment of lignocellulosic materials under acidic conditions typical of autohydrolysis. The model was used to predict the general trend of hemi-cellulose and cellulose hydrolysis between pH 2 and 4 and temperatures of 170-230 degrees C, and results were compared with experimental data. When the model was evaluated for this range of temperatures and pH values, results indicated: (1) a relatively low temperature (175 degrees C) during the first stage allows hydrolysis of the hemi-cellulose polysaccharides without significant mono-saccharide decomposition, (2) subsequent stages at higher temperatures (equal or greater than 200 degrees C) are needed for significant cellulose hydrolysis, but glucose decomposition will also occur, and, (3) a pH in the range of 2-2.5 will enhance polysaccharide hydrolysis while limiting monosaccharide decomposition. The model's predictions, indicating that the formation of biodegradable products could be optimized using Pretreatments at pH 2-2.5 for the pH range evaluated, were confirmed in experiments with white fir as a representative lig nocellulose.
View details for Web of Science ID A1988L611800009
View details for PubMedID 18581564
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ABIOTIC AND BIOTIC TRANSFORMATIONS OF 1,1,1-TRICHLOROETHANE UNDER METHANOGENIC CONDITIONS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1987; 21 (12): 1208-1213
View details for Web of Science ID A1987L063200015
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OPERATIONAL EXPERIENCES WITH ACTIVATED CARBON ADSORBERS AT WATER FACTORY 21
JOURNAL OF ENVIRONMENTAL PATHOLOGY TOXICOLOGY AND ONCOLOGY
1987; 7 (7-8): 319-338
View details for Web of Science ID A1987L461800022
View details for PubMedID 3694480
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TRANSFORMATIONS OF HALOGENATED ALIPHATIC-COMPOUNDS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1987; 21 (8): 722-736
View details for Web of Science ID A1987J403100004
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ES Critical Reviews: Transformations of halogenated aliphatic compounds.
Environmental science & technology
1987; 21 (8): 722-736
View details for DOI 10.1021/es00162a001
View details for PubMedID 19995052
- Column Methodologies for Determining Sorption and Biotransformation Potential for Chlorinated Aliphatic Compounds in Aquifers Journal of Contaminant Hydrology 1987; 2: 31-50
- Removal of Organic Substances from Water by Air Stripping Control of Organic Substances in Water and Wastewater edited by Berger, B. B. Noyes Publications. 1987: 119–147
- Rate of Abiotic Formation of 1,1-Dichloroethylene from 1,1,1-Trichloroethane in Groundwater Journal of Contaminant Hydrology 1987; 1: 299-308
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ANAEROBIC WASTE-WATER TREATMENT .4.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1986; 20 (12): 1200-1206
View details for Web of Science ID A1986F016100003
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REMOVING TRACE ORGANICS BY REVERSE-OSMOSIS USING CELLULOSE-ACETATE AND POLYAMIDE MEMBRANES
JOURNAL AMERICAN WATER WORKS ASSOCIATION
1986; 78 (4): 163-174
View details for Web of Science ID A1986A742900004
- Reduction of Hexachloroethane to Tetrachloroethylene in Groundwater Journal of Contaminant Hydrology 1986; 1 (1/2): 133-142
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NUMERICAL-SIMULATION OF MIXED-CULTURE BIOFILM - CLOSURE
JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE
1985; 111 (4): 549-551
View details for Web of Science ID A1985ANE0300015
- Effect of Hydrogen Concentration on Population Distribution and Kinetics in Methanogenesis of Propionate Biotechnological Advances in Processing Municipal Wastes for Fuels and Chemicals edited by Antonopoulos, A. A. Argonne National Laboratory. 1985: 53–66
- Processes Affecting the Movement and Fate of Trace Organics in the Subsurface Environment Artificial Recharge of Groundwater edited by Asano, T. Butterworth Publishers. 1985: 627–646
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ETHYLENE DIBROMIDE TRANSFORMATION UNDER METHANOGENIC CONDITIONS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1985; 50 (2): 527-528
Abstract
Ethylene dibromide present at a low concentration (less than 100 micrograms/liter) was transformed by reductive dehalogenation under methanogenic conditions in batch bacterial cultures and in a continuous-flow, methanogenic, fixed-film, laboratory-scale column.
View details for Web of Science ID A1985ANR7600052
View details for PubMedID 3901923
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UTILIZATION RATES OF TRACE HALOGENATED ORGANIC-COMPOUNDS IN ACETATE-GROWN BIOFILMS
BIOTECHNOLOGY AND BIOENGINEERING
1985; 27 (11): 1564-1571
Abstract
Trace concentrations of chlorinated benzenes and chlorinated aliphatics were biotransformed by acetate-supported biofilms, the former under aerobic conditions and the latter under methanogenic conditions. The rates of transformation of the halogenated organic compounds (secondary substrates) differed from that of acetate, the primary substrate; some were higher, some were lower, and some were similar. Factors affecting the relative rates of utilization in multisubstrate systems are not known.
View details for Web of Science ID A1985ATH8100006
View details for PubMedID 18553609
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BIOTRANSFORMATION OF TETRACHLOROETHYLENE TO TRICHLOROETHYLENE, DICHLOROETHYLENE, VINYL-CHLORIDE, AND CARBON-DIOXIDE UNDER METHANOGENIC CONDITIONS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1985; 49 (5): 1080-1083
Abstract
Tetrachloroethylene (PCE) and trichloroethylene (TCE), common industrial solvents, are among the most frequent contaminants found in groundwater supplies. Due to the potential toxicity and carcinogenicity of chlorinated ethylenes, knowledge about their transformation potential is important in evaluating their environmental fate. The results of this study confirm that PCE can be transformed by reductive dehalogenation to TCE, dichloroethylene, and vinyl chloride (VC) under anaerobic conditions. In addition, [14C]PCE was at least partially mineralized to CO2. Mineralization of 24% of the PCE occurred in a continuous-flow fixed-film methanogenic column with a liquid detention time of 4 days. TCE was the major intermediate formed, but traces of dichloroethylene isomers and VC were also found. In other column studies under a different set of methanogenic conditions, nearly quantitative conversion of PCE to VC was found. These studies clearly demonstrate that TCE and VC are major intermediates in PCE biotransformation under anaerobic conditions and suggest that potential exists for the complete mineralization of PCE to CO2 in soil and aquifer systems and in biological treatment processes.
View details for Web of Science ID A1985AGU0500011
View details for PubMedID 3923927
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PERFORMANCE-CHARACTERISTICS OF THE ANAEROBIC BAFFLED REACTOR
WATER RESEARCH
1985; 19 (1): 99-106
View details for Web of Science ID A1985AAH4600014
- Ground Water Quality edited by Ward, C. H., Giger, W., McCarty, P. L. John Wiley & Sons, Inc.. 1985
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NUMERICAL-SIMULATION OF MIXED-CULTURE BIOFILM
JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE
1984; 110 (2): 393-411
View details for Web of Science ID A1984SM27000008
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Microbiological Processes Affecting Chemical Transformations in Groundwater
Groundwater Pollution Microbiology
edited by Bitton, G., Gerba, C. P.
John Wiley & Sons, Inc.. 1984: 89–115
View details for DOI 5
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MODELING OF TRACE ORGANICS BIOTRANSFORMATION IN THE SUBSURFACE
GROUND WATER
1984; 22 (4): 433-440
View details for Web of Science ID A1984SY29300007
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SECONDARY SUBSTRATE UTILIZATION OF METHYLENE-CHLORIDE BY AN ISOLATED STRAIN OF PSEUDOMONAS SP
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1984; 47 (4): 825-830
Abstract
Secondary substrate utilization of methylene chloride was analyzed by using Pseudomonas sp. strain LP. Both batch and continuously fed reactors demonstrated that this strain was capable of simultaneously consuming two substrates at different concentrations: the primary substrate at the higher concentration (milligrams per liter) and the secondary substrate at the lower concentration (micrograms per liter). The rate of methylene chloride utilization at trace concentrations was greater in the presence of the primary substrate, acetate, than without it. However, when the substrate roles were changed, the acetate secondary substrate utilization rate was less when methylene chloride was present. Thus, substrate interactions are important in the kinetics of secondary substrate utilization. Pseudomonas sp. strain LP showed a preference toward degrading methylene chloride over acetate, whether it was the primary or secondary substrate, providing it was below an inhibitory concentration of ca. 10 mg/liter.
View details for Web of Science ID A1984SL52400040
View details for PubMedID 6721491
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CHEMICAL INDICATORS AND SURROGATE PARAMETERS IN WATER-TREATMENT
JOURNAL AMERICAN WATER WORKS ASSOCIATION
1984; 76 (10): 98-106
View details for Web of Science ID A1984TT43600013
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THE EFFECT OF THERMAL PRETREATMENT ON THE ANAEROBIC BIODEGRADABILITY AND TOXICITY OF WASTE ACTIVATED-SLUDGE
WATER RESEARCH
1984; 18 (11): 1343-1353
View details for Web of Science ID A1984TN14500002
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ORGANIC CONTAMINANT BEHAVIOR DURING RAPID INFILTRATION OF SECONDARY WASTEWATER AT THE PHOENIX 23RD AVENUE PROJECT
WATER RESEARCH
1984; 18 (4): 463-472
View details for Web of Science ID A1984SJ83200011
- Biofilm Transformations of Trace Organic Compounds in Groundwater Biofilm Processes in Ground Water Research Ecological Research Committee of NFR, Sweden. 1984: 91–111
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TRANSFORMATIONS OF 1-CARBON AND 2-CARBON HALOGENATED ALIPHATIC ORGANIC-COMPOUNDS UNDER METHANOGENIC CONDITIONS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1983; 45 (4): 1286-1294
Abstract
Several 1- and 2-carbon halogenated aliphatic organic compounds present at low concentrations (less than 100 micrograms/liter) were degraded under methanogenic conditions in batch bacterial cultures and in a continuous-flow methanogenic fixed-film laboratory-scale column. Greater than 90% degradation was observed within a 2-day detention time under continuous-flow methanogenic conditions with acetate as a primary substrate. Carbon-14 measurements indicated that chloroform, carbon tetrachloride, and 1,2-dichloroethane were almost completely oxidized to carbon dioxide, confirming removal by biooxidation. The initial step in the transformations of tetrachloroethylene and 1,1,2,2-tetrachloroethane to nonchlorinated end products appeared to be reductive dechlorination to trichloroethylene and 1,1,2-trichloroethane, respectively. Transformations of the brominated aliphatic compounds appear to be the result of both biological and chemical processes. The data suggest that transformations of halogenated aliphatic compounds can occur under methanogenic conditions in the environment.
View details for Web of Science ID A1983QK23700020
View details for PubMedID 6859849
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Autohydrolysis for Increasing Methane Yields from Lignocellulosic Materials
Fuel Gas Developments
edited by Wise, D. L.
CRC Press, Inc.. 1983: 49–72
View details for DOI 3
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EFFECTS OF 2-BROMOETHANESULFONIC ACID AND 2-CHLOROETHANESULFONIC ACID ON ACETATE UTILIZATION IN A CONTINUOUS-FLOW METHANOGENIC FIXED-FILM COLUMN
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1983; 45 (4): 1408-1410
Abstract
2-Bromoethanesulfonic acid (BESA) and 2-chloroethanesulfonic acid (CESA) have been reported to be potent inhibitors of methane formation during methanogenic decomposition in batch cultures. However, in a laboratory-scale continuous-flow methanogenic fixed-film column containing a predominance of acetate-decarboxylating methanogens, BESA at 6 x 10 M produced only a 41% inhibition of acetate utilization, and CESA at 5.4 x 10 M produced a 37% inhibition of acetate utilization. BESA and CESA concentrations were not monitored in the effluent, so their fate is unknown. The organisms in the column were capable of degrading trace halogenated aliphatic compounds ( approximately 30 mug/liter) with acetate (100 mg/liter) as the primary substrate. Previous exposure of the cells to halogenated organic compounds may have conferred resistance to BESA and CESA. Degradation of the inhibitor compounds is another possible explanation for the observed effects.
View details for Web of Science ID A1983QK23700040
View details for PubMedID 16346280
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TRANSFORMATIONS OF HALOGENATED ORGANIC-COMPOUNDS UNDER DENITRIFICATION CONDITIONS
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1983; 45 (4): 1295-1299
Abstract
Trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dibromoethane, chlorinated benzenes, ethylbenzene, and naphthalene at concentrations commonly found in surface and groundwater were incubated under anoxic conditions to study their transformability in the presence of denitrifying bacteria. None of the aromatic compounds showed significant utilization relative to sterile controls at initial concentrations from 41 to 114 micrograms/liter after 11 weeks of incubation. Of the halogenated aliphatic compounds studied, transformations of carbon tetrachloride and brominated trihalomethanes were observed after 8 weeks in batch denitrification cultures. Carbon from the decomposition of carbon tetrachloride was both assimilated into cell material and mineralized to carbon dioxide. How this was possible remains unexplained, since carbon tetrachloride is transformed to CO2 by hydrolysis and not by oxidation-reduction. Chloroform was detected in bacterial cultures with carbon tetrachloride initially present, indicating that reductive dechlorination had occurred in addition to hydrolysis. The data suggest that transformations of certain halogenated aliphatic compounds are likely to occur under denitrification conditions in the environment.
View details for Web of Science ID A1983QK23700021
View details for PubMedID 6859850
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Model of steady-state-biofilm kinetics.
Biotechnology and bioengineering
1982; 24 (10): 2291-?
View details for PubMedID 18546138
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ANAEROBIC DEGRADATION OF HALOGENATED 1-CARBON AND 2-CARBON ORGANIC-COMPOUNDS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1982; 16 (2): 130-130
View details for Web of Science ID A1982MZ52100022
- Correspondence on: Anaerobic Degradation of Halogenated 1- and 2-Carbon Organic Compounds Environmental Science and Technology 1982: 130
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REMOVAL OF TRACE CHLORINATED ORGANIC-COMPOUNDS BY ACTIVATED CARBON AND FIXED-FILM BACTERIA
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1982; 16 (12): 836-843
View details for Web of Science ID A1982PS89200011
View details for PubMedID 22236258
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HEAT-TREATMENT AND ANAEROBIC-DIGESTION OF REFUSE
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1982; 108 (3): 437-454
View details for Web of Science ID A1982NS42800001
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TRACE ORGANICS IN GROUNDWATER
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1981; 15 (1): 40-?
View details for Web of Science ID A1981KW80400007
- Water and Its Challenges The Stanford Engineer Stanford School of Engineering. 1981: 23–31
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Heat Treatment of Organic Materials for Increasing Anaerobic Biodegradability
Fuel Gas Production from Biomass
edited by Wise, D. L.
CRC Press, Inc.. 1981: 133–176
View details for DOI 6
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A COMPARISON OF THE CHARACTERISTICS OF SOLUBLE ORGANIC NITROGEN IN UNTREATED AND ACTIVATED-SLUDGE TREATED WASTEWATERS
WATER RESEARCH
1981; 15 (1): 139-149
View details for Web of Science ID A1981KY04900021
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CHARACTERIZATION AND METHANE FERMENTATION OF SOLUBLE PRODUCTS FROM STAGED AUTOHYDROLYSIS OF WOOD
BIOTECHNOLOGY AND BIOENGINEERING
1981: 113-124
View details for Web of Science ID A1981NC63200012
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PRODUCTION OF SOLUBLE ORGANIC NITROGEN DURING ACTIVATED-SLUDGE TREATMENT
JOURNAL WATER POLLUTION CONTROL FEDERATION
1981; 53 (1): 99-112
View details for Web of Science ID A1981KZ89800016
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SOURCES OF SOLUBLE ORGANIC NITROGEN IN ACTIVATED-SLUDGE EFFLUENTS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1981; 53 (1): 89-98
View details for Web of Science ID A1981KZ89800015
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SUBSTRATE FLUX INTO BIOFILMS OF ANY THICKNESS
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1981; 107 (4): 831-849
View details for Web of Science ID A1981LZ72900015
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ANAEROBIC DEGRADATION OF HALOGENATED 1-CARBON AND 2-CARBON ORGANIC-COMPOUNDS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1981; 15 (5): 596-599
View details for Web of Science ID A1981LN35700025
View details for PubMedID 22283955
- One Hundred Years of Anaerobic Treatment Anaerobic Digestion 1981 edited by Hughes, H. Elsevier Biomedical Press, Inc.. 1981: 3–22
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TRACE ORGANIC BEHAVIOR IN SOIL COLUMNS DURING RAPID INFILTRATION OF SECONDARY WASTE-WATER
WATER RESEARCH
1981; 15 (1): 151-159
View details for Web of Science ID A1981KY04900022
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ORGANIC CONTAMINANT BEHAVIOR DURING GROUNDWATER RECHARGE
JOURNAL WATER POLLUTION CONTROL FEDERATION
1980; 52 (1): 161-172
View details for Web of Science ID A1980JD17700019
- Organic Materials Formed Through Decolorization of Coffee Wastewater with Chlorine and Chlorine Dioxide Water Chlorination, Environmental Impact and Health Effects edited by Jolly, R. L. Ann Arbor Science Publishers. 1980: 315–323
- Processes Affecting the Movement and Fate of Trace Organics in the Subsurface Environment Wastewater Reuse for Groundwater Recharg edited by Asano, T., Roberts, P. V. California State Water Resources Control Board. 1980: 93–117
- Reliability of Water Factory 21 Wastewater Reuse for Groundwater Recharge edited by Asano, T., Roberts, P. V. California State Water Resources Control Board. 1980: 55–72
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ORGANICS IN WATER - AN ENGINEERING CHALLENGE
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1980; 106 (1): 1-17
View details for Web of Science ID A1980JP27700001
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ANAEROBIC TOXICITY EVALUATION BY BATCH AND SEMI-CONTINUOUS ASSAYS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1980; 52 (4): 720-729
View details for Web of Science ID A1980JS10800010
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FEASIBILITY OF A PEAT BIOGASIFICATION PROCESS
RESOURCE RECOVERY AND CONSERVATION
1980; 5 (2): 117-138
View details for Web of Science ID A1980KB74000001
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UTILIZATION OF DICHLOROMETHANE BY SUSPENDED AND FIXED-FILM BACTERIA
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
1980; 39 (6): 1225-1226
Abstract
Dichloromethane (methylene chloride) was biodegraded by and supported growth of suspended and fixed-film bacteria enriched from sewage.
View details for Web of Science ID A1980JW98100024
View details for PubMedID 16345585
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TRACE-ORGANICS BIODEGRADATION IN AQUIFER RECHARGE
GROUND WATER
1980; 18 (3): 236-243
View details for Web of Science ID A1980JQ98800004
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DESIGN OF FIXED-FILM PROCESSES WITH STEADY-STATE-BIOFILM MODEL
PROGRESS IN WATER TECHNOLOGY
1980; 12 (6): 271-281
View details for Web of Science ID A1980KZ67600018
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MODEL OF STEADY-STATE-BIOFILM KINETICS
BIOTECHNOLOGY AND BIOENGINEERING
1980; 22 (11): 2343-2357
View details for Web of Science ID A1980KR26400009
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EVALUATION OF STEADY-STATE-BIOFILM KINETICS
BIOTECHNOLOGY AND BIOENGINEERING
1980; 22 (11): 2359-2373
View details for Web of Science ID A1980KR26400010
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TRACE ORGANICS REMOVAL BY ADVANCED WASTEWATER-TREATMENT
JOURNAL WATER POLLUTION CONTROL FEDERATION
1980; 52 (7): 1907-1922
View details for Web of Science ID A1980KB91800006
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TRACE ORGANICS REMOVAL BY ADVANCED WASTE TREATMENT
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1979; 105 (4): 675-693
View details for Web of Science ID A1979HL80500005
- Volatile Organic Contaminants Removal by Air Stripping Seminar on Controlling Organics in Drinking Water American Water Works Association. 1979
- Thermochemical Pretreatment of Nitrogenous Materials to Increase Methane Yield Biotechnology and Bioengineering Symposium John Wiley & Sons. 1979: 219–233
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BIOASSAY FOR MONITORING BIOCHEMICAL METHANE POTENTIAL AND ANAEROBIC TOXICITY
WATER RESEARCH
1979; 13 (6): 485-492
View details for Web of Science ID A1979GX19100003
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REMOVAL OF SOLUBLE SECONDARY-EFFLUENT ORGANICS
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1979; 105 (4): 727-743
View details for Web of Science ID A1979HL80500008
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OPERATIONAL EXPERIENCES WITH ACTIVATED CARBON ADSORBERS AT WATER FACTORY 21
JOURNAL AMERICAN WATER WORKS ASSOCIATION
1979; 71 (11): 683-689
View details for Web of Science ID A1979HX97200013
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INVESTIGATION OF SOLUBLE ORGANIC NITROGEN-COMPOUNDS IN MUNICIPAL SECONDARY EFFLUENT
JOURNAL WATER POLLUTION CONTROL FEDERATION
1978; 50 (11): 2522-2529
View details for Web of Science ID A1978FV01600012
- Effect of Thermal Pretreatment on Digestibility and Dewaterability of Organic Sludges Journal Water Pollution Control Federtion 1978; 50: 73-85
- Chemistry for Environmental Engineers McGraw-Hill Book Company. 1978
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DIRECT INJECTION OF RECLAIMED WATER INTO AN AQUIFER
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1978; 104 (5): 933-949
View details for Web of Science ID A1978FR19700008
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VARIABLE-ORDER MODEL OF BACTERIAL-FILM KINETICS
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1978; 104 (5): 889-900
View details for Web of Science ID A1978FR19700005
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ANAEROBIC DIGESTION OF SLUDGE FROM CHEMICAL TREATMENT
JOURNAL WATER POLLUTION CONTROL FEDERATION
1978; 50 (3): 533-542
View details for Web of Science ID A1978EU09900016
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VARIATIONS IN NITROGEN AND ORGANICS IN WASTEWATERS
JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE
1977; 103 (4): 539-550
View details for Web of Science ID A1977DP27700002
- Fundamental Research Needs in Wastewater Treatment for Biological Processes Fundamental Research Needs for Water and Wastewater Treatment Systems edited by Sherrard, J. H. National Science Foundation. 1977: 72–76
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VERIFICATION STUDIES OF BIOFILM MODEL FOR BACTERIAL SUBSTRATE UTILIZATION
JOURNAL WATER POLLUTION CONTROL FEDERATION
1976; 48 (2): 281-296
View details for Web of Science ID A1976BG79600005
- Heat Treatment of Refuse for Increasing Anaerobic Biodegradability Biochemical Engineering––Energy, Renewable Resources and New Foods American Institute of Chemical Engineers. 1976; 158: 64–71
- Heat Treatment for Increasing Methane Yields from Organic Materials Microbial Energy Conversion edited by Schlegel, H. G., Barnes, J. Erich Golze KG. 1976: 179–199
- Kinetics of Biological Decomposition of Methylmercury Environmental Biogeochemistry edited by Nriagu, J. O. Ann Arbor Science. 1976: 451–472
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MODEL OF SUBSTRATE UTILIZATION BY BACTERIAL FILMS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1976; 48 (1): 9-24
View details for Web of Science ID A1976BD79300001
View details for PubMedID 1255905
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MULTI-PROCESS BIOLOGICAL TREATMENT MODEL
JOURNAL WATER POLLUTION CONTROL FEDERATION
1975; 47 (11): 2652-2664
View details for Web of Science ID A1975AW42100010
View details for PubMedID 1219142
- Characteristics and Removal of Soluble Organic Nitrogen in Treated Effluents Progress in Water Technology 1975; 7: 435-445
- Stoichiometry of Biological Reactions Progress in Water Technology 1975; 7: 157-172
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FIELD STUDIES OF NITRIFICATION WITH SUBMERGED FILTERS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1975; 47 (2): 291-309
View details for Web of Science ID A1975V636800009
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RAPID MEASUREMENT OF MONOD HALF-VELOCITY COEFFICIENTS FOR BACTERIAL KINETICS
BIOTECHNOLOGY AND BIOENGINEERING
1975; 17 (6): 915-924
View details for Web of Science ID A1975AG75900008
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OXIDATION OF CINNABAR BY FE(III) IN ACID MINE WATERS
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1975; 9 (7): 676-678
View details for Web of Science ID A1975AG47300018
- The Water Studies Program at Stanford University Civil Engineering Education 1974; 1 (1): 193-199
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NITRIFICATION WITH SUBMERGED FILTERS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1972; 44 (11): 2086-?
View details for Web of Science ID A1972N966900004
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Energetics of Organic Matter Degradation,
Microbiology of Polluted Waters
edited by Mitchell, R.
John Wiley & Sons. 1972: 91–118
View details for DOI 5
- Energetics and Bacterial Growth Organic Compounds in Aquatic Environments edited by Faust, S. D., Hunter, J. V. Marcel Dekker, Inc.. 1971: 495–531
- Nitrogen Removal from Waste Waters by Biological Nitrification and Denitrification Microbial Aspects of Pollution edited by Sykes, G., Skinner, F. A. Academic Press. 1971
- Energetics and Kinetics of Anaerobic Treatment Anaerobic Biological Treatment Process edited by Pohland, F. 1971: 91–107
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EFFECTS OF CARBONATE AND MAGNESIUM ON CALCIUM PHOSPHATE PRECIPITATION
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1971; 5 (6): 534-?
View details for Web of Science ID A1971J475000016
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Energetics and Bacterial Growth
Organic Compounds in Aquatic Environments
Marcel Dekker, Inc. . 1971: 495–531
View details for DOI 21
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AEROBIC DECOMPOSITION OF ALGAE
ENVIRONMENTAL SCIENCE & TECHNOLOGY
1971; 5 (10): 1023-?
View details for Web of Science ID A1971K464300014
- Chemistry of Nitrogen and Phosphorus in Water Journal American Water Works Association 1970; 62: 127-140
- Unified Basis for Biological Treatment Design and Operation Journal Sanitary Engineering Division 1970; 96 (SA3): 757-778
- The Extent of Nitrogen and Phosphorus Regeneration from Decomposing Algae Advances in Water Pollution Research edited by Jenkins, S. H. Pergamon Press. 1970: III27/1–15
- The Decomposition of Algae in Anaerobic Waters Environmental Science and Technology 1970; 4: 842-849
- Biological Processes for Nitrogen Removal––Theory and Application University of Illinois Bulletin 1970; 68 (2): 136-152
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ANAEROBIC FILTER FOR WASTE TREATMENT
JOURNAL WATER POLLUTION CONTROL FEDERATION
1969; 41 (5P2): R160-?
View details for Web of Science ID A1969D340500004
View details for PubMedID 5791941
- Evaluation of Nitrification in Streams, A Discussion Journal of Sanitary Engineering Division 1969; 95 (SA5): 952-955
- Graphical Evaluation of the Kinetic Parameters for Bacterial Growth Canadian Journal Microbiology 1969; 15: 1201-1205
- Kinetics of Methane Fermentation in Anaerobic Treatment Journal Water Pollution Control Federation 1969; 41: R1-R17
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TREATMENT OF HIGH NITRATE WATERS
JOURNAL AMERICAN WATER WORKS ASSOCIATION
1969; 61 (12): 659-?
View details for Web of Science ID A1969F072000005
- Advances in Water Pollution Research Advances in Water Quality Improvement edited by Gloyna, E. F., Eckenfelder, W. W. Universitiy of Texas Press. 1968: 336–352Advances in Water Quality Improvement
- A Chromatic Model for Predicting Pesticide Migration in Soils, Soil Science 1968; 106: 248-261
- Enzymes in Waste Treatment Bulletin, California Water Pollution Control Association 1967; 3: 35-36
- Prediction of Nitrification Effects on the Dissolved Oxygen Balance in Streams Environmental Science and Technology 1967; 1: 405-410
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ANAEROBIC DEGRADATION OF SELECTED CHLORINATED HYDROCARBON PESTICIDES
JOURNAL WATER POLLUTION CONTROL FEDERATION
1967; 39 (8): 1259-?
View details for Web of Science ID A19679854000001
View details for PubMedID 6074484
- Sources of Nitrogen and Phosphorus in Water Supplies Journal American Water Works Association 1967; 59: 344-366
- Chemistry for Sanitary Engineers McGraw-Hill Book Company. 1967
- Discussion of the Role of Enzymes in Contact Stabilization Process Advances in Water Pollution Research edited by Siddigi, R. H., Englebrecht, R. S. Water Pollution Control Federation. 1967: 372–376
- Proceedings of the National Symposium on Estuarine Pollution edited by McCarty, P. L., Kennedy, R. Stanford University. 1967
- Nutrient Associated Problems in Water Quality and Treatment Journal American Water Works Association 1966; 58
- The Effects of Sulfides on Anaerobic Treatment International Journal of Air and Water Pollution 1966; 10: 207-221
- Kinetics of Waste Assimilation in Anaerobic Treatment Developments in Industrial Microbiology American Institute of Biological Sciences. 1966: 144–155
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SLUDGE CONCENTRATION - NEEDS ACCOMPLISHMENTS AND FUTURE GOALS
JOURNAL WATER POLLUTION CONTROL FEDERATION
1966; 38 (4): 493-?
View details for Web of Science ID A19667671200001
View details for PubMedID 5929839
- The Role of Sulfides in Preventing Heavy Metal Toxicity in Anaerobic Digestion Journal Water Pollution Control Federation 1965; 37: 392-406
- Cation Toxicity and Stimulation in Anaerobic Waste Treatment Journal Water Pollution Control Federation 1965; 37: 97-116
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THERMODYNAMICS OF BIOLOGICAL SYNTHESIS AND GROWTH
AIR AND WATER POLLUTION
1965; 9 (10): 621-639
View details for Web of Science ID A1965CLS7500004
View details for PubMedID 5837726
- Biochemistry of Methane Fermentation Using C14 Tracers JOURNAL OF WATER POLLUTION CONTROL FEDERATION 1965; 37: 178-192
- Anaerobic Waste Treatment Fundamentals. Part III, Toxic Materials and Their Control Public Works 1964; 95: 91-94
- Nutrient Requirements and Biological Solids Accumulation in Anaerobic Digestion Advances in Water Pollution Research Pergamon Press. 1964: 305–322
- Anaerobic Waste Treatment Fundamentals. Part II, Environmental Requirements and Control Public Works 1964; 95: 123-126
- Research and Development for Reuse of Water Water; Development, Utilization, Conservation edited by McNickle, R. K. University of Colorado Press. 1964: 55–59
- Anaerobic Waste Treatment Fundamentals. Part IV, Process Design Public Works 1964; 95: 95-99
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The Methane Fermentation
Principles and Applications in Aquatic Microbiology
edited by Heukelekian, H., Dondero, N. C.
John Wiley. 1964: 314–343
View details for DOI 16
- Anaerobic Waste Treatment Fundamentals. Part I, Chemistry and Microbiology Public Works 1964; 95: 107-112
- Free Energy as a Parameter in Biological Treatment, A Discussion Journal Sanitary Engineering Division 1963; 89 (SA6): 65-68
- Significance of Individual Volatile Acids in Anaerobic Treatment JOURNAL OF WATER POLLUTION CONTROL FEDERATION 1963; 35: 1501-1516
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VOLATILE ACID DIGESTION AT HIGH LOADING RATES
INTERNATIONAL JOURNAL OF AIR AND WATER POLLUTION
1962; 6 (1): 65-73
View details for Web of Science ID A1962WY90200005
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THEORY OF EXTENDED AERATION ACTIVATED SLUDGE
JOURNAL WATER POLLUTION CONTROL FEDERATION
1962; 34 (11): 1095-1103
View details for Web of Science ID A1962XL76900001
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SALT TOXICITY IN ANAEROBIC DIGESTION
JOURNAL WATER POLLUTION CONTROL FEDERATION
1961; 33 (4): 399-415
View details for Web of Science ID A1961XL73700007
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VOLATILE ACID TOXICITY IN ANAEROBIC DIGESTION
JOURNAL WATER POLLUTION CONTROL FEDERATION
1961; 33 (3): 223-232
View details for Web of Science ID A1961XL73600002