Martin Reinhard

All Publications

• Effect of repeated sorption-desorption on irreversible and reversible absorption of hydrophobic perfluoroalkyl acids to freshwater sediment ENVIRONMENTAL TECHNOLOGY & INNOVATION Chen, H., Reinhard, M., You, L., Gin, K. 2022; 28

  View details for DOI 10.1016/j.eti.2022.102673

  View details for Web of Science ID 000809657100012

• One planet: one health. A call to support the initiative on a global science-policy body on chemicals and waste. Environmental sciences Europe Brack, W., Barcelo Culleres, D., Boxall, A. B., Budzinski, H., Castiglioni, S., Covaci, A., Dulio, V., Escher, B. I., Fantke, P., Kandie, F., Fatta-Kassinos, D., Hernandez, F. J., Hilscherova, K., Hollender, J., Hollert, H., Jahnke, A., Kasprzyk-Hordern, B., Khan, S. J., Kortenkamp, A., Kummerer, K., Lalonde, B., Lamoree, M. H., Levi, Y., Lara Martin, P. A., Montagner, C. C., Mougin, C., Msagati, T., Oehlmann, J., Posthuma, L., Reid, M., Reinhard, M., Richardson, S. D., Rostkowski, P., Schymanski, E., Schneider, F., Slobodnik, J., Shibata, Y., Snyder, S. A., Fabriz Sodre, F., Teodorovic, I., Thomas, K. V., Umbuzeiro, G. A., Viet, P. H., Yew-Hoong, K. G., Zhang, X., Zuccato, E. 2022; 34 (1): 21

  Abstract

  The chemical pollution crisis severely threatens human and environmental health globally. To tackle this challenge the establishment of an overarching international science-policy body has recently been suggested. We strongly support this initiative based on the awareness that humanity has already likely left the safe operating space within planetary boundaries for novel entities including chemical pollution. Immediate action is essential and needs to be informed by sound scientific knowledge and data compiled and critically evaluated by an overarching science-policy interface body. Major challenges for such a body are (i) to foster global knowledge production on exposure, impacts and governance going beyond data-rich regions (e.g., Europe and North America), (ii) to cover the entirety of hazardous chemicals, mixtures and wastes, (iii) to follow a one-health perspective considering the risks posed by chemicals and waste on ecosystem and human health, and (iv) to strive for solution-oriented assessments based on systems thinking. Based on multiple evidence on urgent action on a global scale, we call scientists and practitioners to mobilize their scientific networks and to intensify science-policy interaction with national governments to support the negotiations on the establishment of an intergovernmental body based on scientific knowledge explaining the anticipated benefit for human and environmental health.

  View details for DOI 10.1186/s12302-022-00602-6

  View details for PubMedID 35281760

• Quantification of cylindrospermopsin, anatoxin-a and homoanatoxin-a in cyanobacterial bloom freshwater using direct injection/SPE coupled with UPLC-MS/MS. The Science of the total environment Tran, N. H., Li, Y. n., Reinhard, M. n., Goh, K. C., Sukarji, N. H., You, L. n., He, Y. n., Gin, K. Y. 2020; 731: 139014

  Abstract

  Analytical methods based on direct injection (DI) and solid phase extraction (SPE) coupled with ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC- MS/MS) were developed for the determination of anatoxin-a (ATX-a), cylindrospermopsin (CYN), and homoanatoxin-a (HATX-a) in freshwater samples impacted with cyanobacterial blooms. The presence of CYN in freshwater samples was detected and quantified based on direct injection method, while ATX-a and HATX-a could be determined by both DI and SPE-based methods. Matrix effects (ME) on the signal intensity of the cyanotoxins were systematically evaluated for both direct injection and SPE extract samples. CYN, ATX-a, and HATX-a suffered a significant suppression during UPLC-MS/MS. The selection of internal standards (ISs) for compensating/correcting the losses of target cyanotoxins during sample preparation and matrix effects in UPLC-MS/MS analyses were systematically evaluated. Acetaminophen-d4 (an isotopically labelled acetaminophen) is a suitable internal standard for correcting the ME on the signal intensity of ATX-a and HATX-a, while the use of L-phenylalanine-d5 or caffeine-d9 as IS for correcting ME of these toxins was not efficient, as expected. The method detection limit (MDL) for the target cyanotoxins ranged from 0.6 to 15 ng/L, which is sensitive enough to detect the presence of these toxins in cyanobacterial bloom freshwater. The developed methods were successfully applied for routine monitoring of the occurrence of these cyanotoxins in a local water body. Monitoring results depicted that ATX-a, CYN and HATX-a were ubiquitously detected in water samples, at concentrations ranging from 70 to 24,600 ng/L.

  View details for DOI 10.1016/j.scitotenv.2020.139014

  View details for PubMedID 32428751

• A sensitive and accurate method for simultaneous analysis of algal toxins in freshwater using UPLC-MS/MS and 15N-microcystins as isotopically labelled internal standards. The Science of the total environment Tran, N. H., Li, Y. n., Reinhard, M. n., He, Y. n., Gin, K. Y. 2020; 738: 139727

  Abstract

  The development of analytical methods for the detection and accurate quantification of algal toxins is of importance to assess the health risk of exposure to algal toxins in freshwater sources. This study established a sensitive and accurate analytical method for the quantification of 13 algal toxins (microcystins and nodularin) based on solid phase extraction (SPE) coupled with UPLC-MS/MS, in which 15N-microcystins were used as surrogate/internal standards. SPE method was optimized to extract the target algal toxins in freshwater samples. Good SPE efficiencies (84-96%) were achieved for the overwhelming majority of the investigated algal toxins when SPE was performed using HLB (500 mg, 6 mL) under alkaline conditions (pH 11). An accurate quantitative analysis of the algal toxins in real freshwater samples was performed by using 15N-labelled microcystins as isotopically labelled internal standards (ILISs), which compensated for the loss of target toxins during the whole analytical process. In addition, ILISs also helped to correct the effects of environmental matrices and instrument fluctuation in UPLC-MS/MS analysis. The limit of method quantification (MQL) for the algal toxins was <2.0 ng/L that is sensitive enough to quantify extremely low levels of target toxins in freshwater samples.

  View details for DOI 10.1016/j.scitotenv.2020.139727

  View details for PubMedID 32535285

• Quantitative assessment of the iron-catalyzed degradation of a polyamide nanofiltration membrane by hydrogen peroxide JOURNAL OF MEMBRANE SCIENCE Yu, L., Ling, R., Chen, J., Reinhard, M. 2019; 588

  View details for DOI 10.1016/j.memsci.2019.05.078

  View details for Web of Science ID 000481577200032

• Emerging contaminants in wastewater, stormwater runoff, and surface water: Application as chemical markers for diffuse sources SCIENCE OF THE TOTAL ENVIRONMENT Ngoc Han Tran, Reinhard, M., Khan, E., Chen, H., Viet Tung Nguyen, Li, Y., Goh, S., Nguyen, Q. B., Saeidi, N., Gin, K. 2019; 676: 252–67

  View details for DOI 10.1016/j.scitotenv.2019.04.160

  View details for Web of Science ID 000468188300025

• Iron catalyzed degradation of an aromatic polyamide reverse osmosis membrane by free chlorine JOURNAL OF MEMBRANE SCIENCE Ling, R., Shao, J., Chen, J., Reinhard, M. 2019; 577: 205–11

  View details for DOI 10.1016/j.memsci.2019.02.010

  View details for Web of Science ID 000459156900021

• Multi-compartment distribution of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in an urban catchment system WATER RESEARCH Chen, H., Reinhard, M., Yin, T., Tung Viet Nguyen, Ngoc Han Tran, Gin, K. 2019; 154: 227–37

  View details for DOI 10.1016/j.watres.2019.02.009

  View details for Web of Science ID 000462104100025

• Multi-compartment distribution of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in an urban catchment system. Water research Chen, H., Reinhard, M., Yin, T., Nguyen, T. V., Tran, N. H., Yew-Hoong Gin, K. 2019; 154: 227–37

  Abstract

  Ecotoxicological risks of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in surface waters are difficult to model because data on PFASs distribution in multiple compartments (sediments, suspended particles and aqueous phase) are difficult to predict. This study quantified the distribution of 21 PFASs including PFCAs: C6-C13 perfluoroalkyl carboxylates, C4, C6, C8 and C10 perfluoroalkane sulfonates, 5 perfluorooctane sulfonamide substances (FOSAMs, including EtFOSA, FOSA, MeFOSAA, EtFOSAA, FOSAA), 2 N-alkyl perfluoroalkane sulfonamidoethanols (MeFOSE and EtFOSE), bis (perfluorooctyl) phosphinic acid (C8/C8 PFPIA), and 5:3 fluorotelomer carboxylic acid (5:3 acid) between bulk water and suspended particles in water column, and pore water and benthic sediments from a tropical urban water body. The distribution of PFASs between sorbed and dissolved phase was largely dependent on the perfluoroalkyl chain length (NCF2). PFCAs with NCF2 > 11 and perfluorodecane sulfonate (PFDS, NCF2 = 10) were found predominantly in the suspended particles and sediments. By contrast, short-chain PFASs (NCF2 ≤ 7) were detected predominantly in the dissolved phase. Sediment acts as a sink for long-chain PFASs while short-chain PFASs are more easily transported via the aqueous phase. Compared with benthic sediments, suspended particles, especially those in the top water layer, carried much higher concentrations of PFASs (by a factor of >100), indicating the stronger sorption capability of suspended particles. The wide variation in PFAS concentrations in suspended particles (PFASs concentrations: < 26.8-1,284 ng/g d.w.) suggests that some suspended particles were preloaded with different concentrations of PFASs in the water column which could highly affect the distribution of PFASs in the aquatic environment. Pore water contained 1-2 times higher concentrations of PFASs (PFASs: <20.25-159.34 ng/L) than overlying bulk water (PFASs: <14.2-79.98 ng/L), indicating the accumulation of PFASs in pore water. Distribution coefficients (KD) were calculated using paired solids concentration and dissolved concentration in both water and sediment column (KD-SP and KD-SED respectively) and were compared with values derived from a laboratory batch experiment. The averaged Log KD-SP/Log KD-SED showed significant positive correlation with NCF2, except for short-chain PFASs (NCF2 <5) which presented higher Log KD values than estimated. The discrepancies found between KD (Log KD-SP > Log KD -desorption > Log KD -sorption > Log KD-SED) suggest that the distribution of PFASs in the field, especially between suspended particles and bulk water could not be well represented by lab results and that using the water concentrations in the bottom layer for estimation of pore water concentrations could lead to bias results.

  View details for PubMedID 30798177

• Emerging contaminants in wastewater, stormwater runoff, and surface water: Application as chemical markers for diffuse sources. The Science of the total environment Tran, N. H., Reinhard, M. n., Khan, E. n., Chen, H. n., Nguyen, V. T., Li, Y. n., Goh, S. G., Nguyen, Q. B., Saeidi, N. n., Gin, K. Y. 2019; 676: 252–67

  Abstract

  Diffuse sources of pollution such as sewer leakages, sewer overflows, illicit discharges and stormwater runoff affect the urban surface water quality but often remain unknown. Therefore, the development of chemical markers for identifying and characterizing the origin of diffuse sources of pollution in urban surface waters is a requisite for protecting and managing urban water resources. In this study, the occurrence of 31 emerging contaminants (ECs) in untreated wastewater, treated wastewater, urban stormwater runoff, agricultural stormwater runoff, and freshwater bodies was investigated. Artificial sweeteners (ASs), pharmaceuticals and personal care products (PPCPs) were more frequently detected in the collected water samples. In raw wastewater, 21 target ECs were detected 100% in the collected samples with median concentrations ranging from 49.6 to 77,721 ng/L, while in freshwater bodies, only 13 compounds were found with detection frequency >50%. The median concentration of the majority of detected ECs in freshwater samples was below 100 ng/L. The suitability of ECs as chemical markers of diffuse sources in an urban watershed was assessed using a suite of criteria, including the detection frequency (DF), detection ratio (DR) (i.e. the ratio between median concentration and method quantification limit of a compound) and attenuation rates (i.e., biodegradation, sorption and abiotic degradation) in wastewater treatment processes. In addition, we propose a new key criterion, the concentration ratio (CR) of labile to conservative compounds, to evaluate the applicability of suitable chemical markers for source tracking. Using this new set of criteria (i.e. CR, DF, DR and attenuation rates), our analysis showed that among the investigated ECs, only acesulfame (ACE), acetaminophen (ACT), cyclamate (CYC), saccharin (SAC) were suitable as chemical markers of diffuse sources in surface waters. For caffeine (CF), N,N-diethyl-meta-toluamide (DEET), crotamiton (CTMT), triclocarban (TCC) and triclosan (TCS), their median concentration ratio to sucralose (SUC) in water bodies was consistently higher than that in raw wastewater, suggesting that these compounds might be unsuitable as chemical markers of sewage leakage in surface waters for this study area.

  View details for PubMedID 31048157

• Biotransformation of Sulfluramid (N-ethyl perfluorooctane sulfonamide) and dynamics of associated rhizospheric microbial community in microcosms of wetland plants CHEMOSPHERE Yin, T., Te, S., Reinhard, M., Yang, Y., Chen, H., He, Y., Gin, K. 2018; 211: 379–89

  Abstract

  Although the use of Sulfluramid (N-ethyl perfluorooctane sulfonamide (N-EtFOSA)) has been restricted by the Stockholm Convention, it is still frequently detected in the environmental matrices and in use in some countries. Employing constructed wetlands as treatment systems requires understanding of the biodegradation process in the rhizosphere and the effect of contaminants on the microbes of wetlands. This study aimed to investigate the interactions between the microbial community and N-EtFOSA under aerobic and anaerobic conditions. Aerobic biotransformation of N-EtFOSA occurred with a half-life of 0.51 day and yielded 85.1 mol% PFOS of after 91 days. Kinetic modelling revealed that cleavage of the SN was the rate-limiting degradation step. Biotransformation was not observed under anaerobic and anoxic conditions, suggesting that N-EtFOSA is recalcitrant to biodegradation without dissolved oxygen. Under aerobic condition, the presence of N-EtFOSA and its biotransformation products decreased the microbial richness and diversity and exerted selective pressure on the microbial community. Enrichment of Methylocaldum was significant (49%) in the presence of N-EtFOSA compared to unexposed conditions (11%), suggesting that Methylocaldum is relatively tolerant to N-EtFOSA and potentially degrading N-EtFOSA. Under anaerobic conditions, the microbial richness and diversity were not significantly altered by the presence of N-EtFOSA. Only Methanomethylovorans increased significantly in the spiked microcosm (30% vs. 20%). These findings provide knowledge for comprehending the contribution of N-EtFOSA to other PFASs in various environmental conditions, information about microbial community changes in response to PFASs and robust microbial species which can degrade N-EtFOSA in the environment.

  View details for PubMedID 30077934

• Degradation of organic compounds during the corrosion of ZVI by hydrogen peroxide at neutral pH: Kinetics, mechanisms and effect of corrosion promoting and inhibiting ions WATER RESEARCH Ling, R., Chen, J., Shao, J., Reinhard, M. 2018; 134: 44–53

  Abstract

  The corrosion of zero valent iron (ZVI) by hydrogen peroxide (H2O2) generates hydroxyl (⋅OH) and other radical oxygen species (ROS) that degrade organic materials. To better understand the factors that govern the ROS formation during the H2O2-induced corrosion, we investigated the degradation of an organic probe compound (acesulfame (ACE)) in slurries of ZVI powder in unbuffered laboratory water at pH 6.5 ± 0.5. Chloride ions accelerated the corrosion of ZVI by H2O2 and the formation ROS and, therefore, the degradation of organic materials. Conversely, slowing corrosion by phosphate buffer inhibited ROS formation and the degradation of organic compounds. The rate of H2O2 decomposition was correlated with the liberation of Fe2+(aq) and the ACE degradation rate. The kinetics of H2O2 decomposition was pseudo-first-order and zero-order at low (<0.04 mM/mg) and high [H2O2]/[ZVI] initial ratios, respectively, and was consistent with Langmuir kinetics. The H2O2 decomposition rate was proportional to the ZVI reactive surface area (SA) and nearly independent of the extent of ZVI oxidation, the presence of a Fe2+(aq) chelating agent, and ⋅OH quenchers (methanol and tert-butanol). Kinetic data suggest a mechanism involving rapid cathodic reduction of H2O2 at the metallic ZVI surface which causes the liberation of Fe2+(aq) that generate ⋅OH via the homogeneous Fenton reaction. The stoichiometric efficiency (SE) of organics degradation ranged from 0.0008% to 0.014% and increased with decreasing H2O2 decomposition rate.

  View details for PubMedID 29407650

• Occurrence and fate of emerging contaminants in municipal wastewater treatment plants from different geographical regions-a review WATER RESEARCH Ngoc Han Tran, Reinhard, M., Gin, K. 2018; 133: 182–207

  Abstract

  Emerging contaminants, such as antibiotics, pharmaceuticals, personal care products, hormones, and artificial sweeteners, are recognized as new classes of water contaminants due to their proven or potential adverse effects on aquatic ecosystems and human health. This review provides comprehensive data on the occurrence of 60 emerging contaminants (ECs) in influent, treated effluent, sludge, and biosolids in wastewater treatment plants (WWTPs). In particular, data on the occurrence of ECs in the influents and effluents of WWTPs are systematically summarized and categorized according to geographical regions (Asia, Europe, and North America). The occurrence patterns of ECs in raw influent and treated effluents of WWTPs between geographical regions were compared and evaluated. Concentrations of most ECs in raw influent in Asian region tend to be higher than those in European and North American countries. Many antibiotics were detected in the influents and effluents of WWTPs at concentrations close to or exceeding the predicted no-effect concentrations (PNECs) for resistance selection. The efficacy of EC removal by sorption and biodegradation during wastewater treatment processes are discussed in light of kinetics and parameters, such as sorption coefficients (Kd) and biodegradation constants (kbiol), and physicochemical properties (i.e. log Kow and pKa). Commonly used sampling and monitoring strategies are critically reviewed. Analytical research needs are identified, and novel investigative approaches for future monitoring studies are proposed.

  View details for PubMedID 29407700

• Occurrence and Fate of Benzophenone-Type UV Filters in a Tropical Urban Watershed ENVIRONMENTAL SCIENCE & TECHNOLOGY Mao, F., You, L., Reinhard, M., He, Y., Gin, K. 2018; 52 (7): 3960–67

  Abstract

  The study investigated the occurrence and fate of seven benzophenone-type UV filters (i.e., 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2',4,4'-tetrahydroxybenzophenone (2,2',4,4'OH-BP), 2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,2'-Dihydroxy-4,4'-dimethoxybenzophenone (2,2'OH-4,4'MeO-BP), 2,2'-dihydroxy-4-methoxybenzophenone (2,2'OH-4MeO-BP), 4-hydroxybenzophenone (4OH-BP), and 4,4'-dihyroxybenzophenone (4DHB)) in a tropical urban watershed consisting of five major tributaries that discharge into a well-managed basin. Total benzophenone concentrations (∑CBPs) varied from 19-230.8 ng L-1 in overlying bulk water, 48-115 ng L-1 in pore water, 295-5813 ng g-1 dry weight (d.w.) in suspended solids, and 6-37 ng g-1 d.w. in surficial sediments, respectively. The tributaries (∑CBPs: 19-231 ng L-1) were the main source of benzophenone compounds entering the basin (∑CBPs: 20-81 ng L-1). In the water column, the vertical concentration profile in the aqueous phase was uniform while concentrations in the suspended solids decreased with depth. Different distribution profiles were also identified for benzophenones in suspended solids and sediments. A preliminary risk assessment suggested that the seven BPs were unlikely to pose ecotoxicological risks to local aquatic organisms except for 2OH-4MeO-BP in the case of an intermittent release.

  View details for PubMedID 29502395

• Catalytic effect of iron on the tolerance of thin-film composite polyamide reverse osmosis membranes to hydrogen peroxide JOURNAL OF MEMBRANE SCIENCE Ling, R., Yu, L., Thi Phuong Thuy Pham, Shao, J., Chen, J., Reinhard, M. 2018; 548: 91–98

  View details for DOI 10.1016/j.memsci.2017.11.009

  View details for Web of Science ID 000419646500011

• Effects of monochloramine and hydrogen peroxide on the bacterial community shifts in biologically treated wastewater CHEMOSPHERE Yang, Y., Cheng, D., Li, Y., Yu, L., Gin, K., Chen, J., Reinhard, M. 2017; 189: 399–406

  Abstract

  Amending feed water with biocide is one of the strategy conventionally used to control biofouling in membrane-based water treatment systems. In this study, the impacts of two biocides, monochloramine (MCA) and hydrogen peroxide (H2O2), on the bacterial community in wastewater samples were investigated at equivalent biocidal efficiency levels. Viable bacterial numbers were determined before and after treatment for 10 min and 60 min using both culture-dependent heterotrophic plate count (HPC) and culture-independent propidium monoazide (PMA)-droplet digital PCR (ddPCR). Shifts of the live bacterial diversity were studied using high-throughput sequencing of 16S rRNA genes and followed by bioinformatics analysis. At the genus level, MCA treatment increased the relative abundance of Mycobacterium, Pseudomonas, Sphingomonas, Clostridium, Streptococcus, Undibacterium, Chryseobacterium and Cloacibacterium, while decreasing Arcobacter, Nitrospira and Sphingobium. H2O2 treatment increased the relative abundance of Anaerolinea and Filimonas, and diminished Denitratisoma and Thauera. The findings of this study suggest a combination of different types of biocide may be the most efficient strategy for biofouling mitigation and increasing membrane treatment efficiency.

  View details for PubMedID 28950119

• Perfluoroalkyl and polyfluoroalkyl substances removal in a full-scale tropical constructed wetland system treating landfill leachate WATER RESEARCH Yin, T., Chen, H., Reinhard, M., Yi, X., He, Y., Gin, K. 2017; 125: 418–26

  Abstract

  Landfill leachate is often an important source of emerging organic contaminants including perfluoroalkyl and polyfluoroalkyl substances (PFASs) requiring proper treatment to protect surface water and groundwater resources. This study investigated the occurrence of PFASs in the leachate of a capped landfill site in Singapore and the efficacy of PFASs removal during flow through a constructed wetland (CW) treatment system. The CW treatment system consists of equalization tank, aeration lagoons, sedimentation tank, reed beds and polishing ponds. Target compounds included 11 perfluoroalkyl acids (PFAAs) (7 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonates (PFSAs)) and 7 PFAA precursors. Although total PFASs concentrations in the leachate varied widely (1269 to 7661 ng/L) over the one-year sampling period, the PFASs composition remained relatively stable with PFCAs consistently being predominant (64.0 ± 3.8%). Perfluorobutane sulfonate (PFBS) concentrations were highly correlated with total PFASs concentrations and could be an indicator for the release of PFASs from this landfill. The release of short-chain PFAAs strongly depended on precipitation whereas concentrations of the other PFASs appeared to be controlled by partitioning. Overall, the CW treatment system removed 61% of total PFASs and 50-96% of individual PFASs. PFAAs were removed most efficiently in the reed bed (42-49%), likely due to the combination of sorption to soils and sediments and plant uptake, whereas most of the PFAA precursors (i.e. 5:3 fluorotelomer carboxylate (5:3 acid), N-substituted perfluorooctane sulfonamides (N-MeFOSAA and N-EtFOSAA)) were removed in the aeration lagoon (>55%) by biodegradation. The sedimentation tank and polishing ponds were relatively inefficient, with only 7% PFASs removal.

  View details for PubMedID 28892769

• Occurrence and removal of multiple classes of antibiotics and antimicrobial agents in biological wastewater treatment processes WATER RESEARCH Ngoc Han Tran, N. H., Chen, H., Reinhard, M., Mao, F., Gin, K. Y. 2016; 104: 461-472

  Abstract

  Very little information on the occurrence and fate of multiple classes of antimicrobials in the aquatic environment is reported for the Southeast Asian region. This study provides the first and comprehensive data on the occurrence of ten different classes of antimicrobials in wastewater samples for Singapore. Among the investigated antimicrobials, 19 out of 21 target compounds were detected in 100% of the collected raw influent samples. Concentrations of the detected antimicrobials in raw influent varied from 23.8 to 43,740 ng/L. Removal of antimicrobials by conventional activated sludge (CAS) and membrane bioreactor (MBR) systems at a local wastewater treatment plant was evaluated. MBR exhibited better performance over CAS for most target antimicrobials. Beta-lactam, glycopeptide, and fluoroquinolone classes were largely eliminated by biological wastewater treatment processes, whereas trimethoprim and lincosamides appeared to be persistent. Effects of physicochemical properties and chemical structures of target antimicrobials on their removal efficiencies/mechanisms during wastewater treatment process were also discussed.

  View details for DOI 10.1016/j.watres.2016.08.040

  View details for Web of Science ID 000386401900048

  View details for PubMedID 27585426

• Simultaneous analysis of multiple classes of antimicrobials in environmental water samples using SPE coupled with UHPLC-ESI-MS/MS and isotope dilution TALANTA Ngoc Han Tran, N. H., Chen, H., Thanh Van Do, T. V., Reinhard, M., Huu Hao Ngo, H. H., He, Y., Gin, K. Y. 2016; 159: 163-173

  Abstract

  A robust and sensitive analytical method was developed for the simultaneous analysis of 21 target antimicrobials in different environmental water samples. Both single SPE and tandem SPE cartridge systems were investigated to simultaneously extract multiple classes of antimicrobials. Experimental results showed that good extraction efficiencies (84.5-105.6%) were observed for the vast majority of the target analytes when extraction was performed using the tandem SPE cartridge (SB+HR-X) system under an extraction pH of 3.0. HPLC-MS/MS parameters were optimized for simultaneous analysis of all the target analytes in a single injection. Quantification of target antimicrobials in water samples was accomplished using 15 isotopically labeled internal standards (ILISs), which allowed the efficient compensation of the losses of target analytes during sample preparation and correction of matrix effects during UHPLC-MS/MS as well as instrument fluctuations in MS/MS signal intensity. Method quantification limit (MQL) for most target analytes based on SPE was below 5ng/L for surface waters, 10ng/L for treated wastewater effluents, and 15ng/L for raw wastewater. The method was successfully applied to detect and quantify the occurrence of the target analytes in raw influent, treated effluent and surface water samples.

  View details for DOI 10.1016/j.talanta.2016.06.006

  View details for Web of Science ID 000381322000024

  View details for PubMedID 27474294

• High activity and regenerability of a palladium-gold catalyst for chloroform degradation JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY Velazquez, J. C., Leekumjorn, S., Hopkins, G. D., Heck, K. N., McPherson, J. S., Wilkens, J. A., Nave, B. S., Reinhard, M., Wong, A. S. 2016; 91 (10): 2590-2596

  View details for DOI 10.1002/jctb.4851

  View details for Web of Science ID 000388291900005

• Using Pseudomonas aeruginosa PAO1 to evaluate hydrogen peroxide as a biofouling control agent in membrane treatment systems. Letters in applied microbiology Yang, Y., Kitajima, M., Pham, T. P., Yu, L., Ling, R., Gin, K. Y., Reinhard, M. 2016

  Abstract

  Hydrogen peroxide (H2 O2 ) is widely used in water treatment for biofouling control and, in conjunction with catalysts, as a powerful oxidant for contaminant destruction. H2 O2 could potentially serve as an antifouling agent in reverse osmosis systems in lieu of chlorine-based disinfectants. The dependence of the biocidal efficiency of H2 O2 on cell density, temperature and H2 O2 concentration by determining the growth, attachment and viability of the model bacterium Pseudomonas aeruginosa PAO1 was studied. For controlling growth of planktonic PAO1 cells, the minimally required H2 O2 concentration depends on the cell density and temperature. The effect of H2 O2 to remove the existing biofilm was found to be effective in the presence of a high concentration bicarbonate (8·4 g l(-1) ), which forms peroxymonocarbonate, a strong oxidant and disinfectant. Treatment with H2 O2 -bicarbonate reduced the density of live PAO1 cells, removed extracellular polymeric substances and lowered the average biofilm thickness while maintaining the integrity of the membrane, suggesting that this type of treatment may be a suitable 'in-place-cleaning' procedure for biofouled membranes.H2 O2 is evaluated as a potential replacement for chlorine to control biofouling in membrane-based water treatment systems. The biocidal efficacy of H2 O2 was evaluated as a function of H2 O2 concentration, cell density and temperature using the model organism Pseudomonas aeruginosa PAO1. Results demonstrated that at low temperatures and low cell densities, bacterial growth and membrane biofouling can be prevented by low H2 O2 concentrations, and existing biofilms could be removed by H2 O2 -bicarbonate mixtures. Findings suggested that H2 O2 could be used as a low cost agent for prevention and controlling biofouling in reverse osmosis applications.

  View details for DOI 10.1111/lam.12674

  View details for PubMedID 27682323

• Fate and transport of perfluoro- and polyfluoroalkyl substances including perfluorooctane sulfonamides in a managed urban water body ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH Nguyen, T. V., Reinhard, M., Chen, H., Gin, K. Y. 2016; 23 (11): 10382-10392

  Abstract

  Transport and fate of perfluoro- and polyfluoroalkyl substances (PFASs) in an urban water body that receives mainly urban runoff was investigated. Water, suspended solids, and sediment samples were collected during the monsoon (wet) and inter-monsoon (dry) season at different sites and depths. Samples were analyzed for C7 to C12 perfluoroalkyl carboxylate homologues (PFCAs) (PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA), perfluorohexane, perfluorooctane, and 6:2-fluorotelomer sulfonate (PFHxS, PFOS, and 6:2FtS, respectively), perfluorooctane sulfonamide (FOSA), N-ethyl FOSA (sulfluramid), N-ethyl sulfonamidoethanol (N-EtFOSE), and N-methyl and N-ethyl sulfonamidoacetic acid (N-EtFOSAA and N-MeFOSAA, respectively). Concentrations in wet samples were only slightly higher. The sum total PFAS (ΣPFAS) concentrations dissolved in the aqueous phase and sorbed to suspended solids (SS) ranged from 107 to 253 ng/L and 11 to 158 ng/L, respectively. PFOA, PFOS, PFNA, PFHxS, and PFDA contributed most (approximately 90 %) to the dissolved ΣPFASs. N-EtFOSA dominated the particulate PFAS burden in wet samples. K D values of PFOA and PFOS calculated from paired SS and water concentrations varied widely (1.4 to 13.7 and 1.9 to 98.9 for PFOA and PFOS, respectively). Field derived K D was significantly higher than laboratory K D suggesting hydrophobic PFASs sorbed to SS resist desorption. The ΣPFAS concentrations in the top sedimentary layer ranged from 8 to 42 μg/kg and indicated preferential accumulation of the strongly sorbing long-chain PFASs. The occurrence of the metabolites N-MeFOSAA, N-EtFOSAA and FOSA in the water column and sediments may have resulted from biological or photochemical transformations of perfluorooctane sulfonamide precursors while the absence of FOSA, N-EtFOSA and 6:2FtS in sediments was consistent with biotransformation.

  View details for DOI 10.1007/s11356-016-6788-9

  View details for Web of Science ID 000377021500009

  View details for PubMedID 27146547

• 3D visualization of the internal nanostructure of polyamide thin films in RO membranes JOURNAL OF MEMBRANE SCIENCE Pacheco, F., Sougrat, R., Reinhard, M., Leckie, J. O., Pinnau, I. 2016; 501: 33-44

  View details for DOI 10.1016/j.memsci.2015.10.061

  View details for Web of Science ID 000368629100004

• Reversible and irreversible sorption of perfluorinated compounds (PFCs) by sediments of an urban reservoir CHEMOSPHERE Chen, H., Reinhard, M., Viet Tung Nguyen, V. T., Gin, K. Y. 2016; 144: 1747-1753

  View details for DOI 10.1016/j.chemosphere.2015.10.055

  View details for Web of Science ID 000367774400221

• Investigation of pharmaceuticals, personal care products and endocrine disrupting chemicals in a tropical urban catchment and the influence of environmental factors SCIENCE OF THE TOTAL ENVIRONMENT You, L., Viet Tung Nguyen, V. T., Pal, A., Chen, H., He, Y., Reinhard, M., Gin, K. Y. 2015; 536: 955-963

  View details for DOI 10.1016/j.scitotenv.2015.06.041

  View details for Web of Science ID 000361189800101

• Emerging contaminants of public health significance as water quality indicator compounds in the urban water cycle. Environment international Pal, A., He, Y., Jekel, M., Reinhard, M., Gin, K. Y. 2014; 71: 46-62

  Abstract

  The contamination of the urban water cycle (UWC) with a wide array of emerging organic compounds (EOCs) increases with urbanization and population density. To produce drinking water from the UWC requires close examination of their sources, occurrence, pathways, and health effects and the efficacy of wastewater treatment and natural attenuation processes that may occur in surface water bodies and groundwater. This paper researches in details the structure of the UWC and investigates the routes by which the water cycle is increasingly contaminated with compounds generated from various anthropogenic activities. Along with a thorough survey of chemicals representing compound classes such as hormones, antibiotics, surfactants, endocrine disruptors, human and veterinary pharmaceuticals, X-ray contrast media, pesticides and metabolites, disinfection-by-products, algal toxins and taste-and-odor compounds, this paper provides a comprehensive and holistic review of the occurrence, fate, transport and potential health impact of the emerging organic contaminants of the UWC. This study also illustrates the widespread distribution of the emerging organic contaminants in the different aortas of the ecosystem and focuses on future research needs.

  View details for DOI 10.1016/j.envint.2014.05.025

  View details for PubMedID 24972248

• Emerging contaminants of public health significance as water quality indicator compounds in the urban water cycle ENVIRONMENT INTERNATIONAL Pal, A., He, Y., Jekel, M., Reinhard, M., Gin, K. Y. 2014; 71: 46-62

  View details for DOI 10.1016/j.envint.2014.05.025

  View details for Web of Science ID 000341745100006

• Environmental and Health Impacts of Artificial Turf: A Review ENVIRONMENTAL SCIENCE & TECHNOLOGY Cheng, H., Hu, Y., Reinhard, M. 2014; 48 (4): 2114-2129

  Abstract

  With significant water savings and low maintenance requirements, artificial turf is increasingly promoted as a replacement for natural grass on athletic fields and lawns. However, there remains the question of whether it is an environmentally friendly alternative to natural grass. The major concerns stem from the infill material that is typically derived from scrap tires. Tire rubber crumb contains a range of organic contaminants and heavy metals that can volatilize into the air and/or leach into the percolating rainwater, thereby posing a potential risk to the environment and human health. A limited number of studies have shown that the concentrations of volatile and semivolatile organic compounds in the air above artificial turf fields were typically not higher than the local background, while the concentrations of heavy metals and organic contaminants in the field drainages were generally below the respective regulatory limits. Health risk assessment studies suggested that users of artificial turf fields, even professional athletes, were not exposed to elevated risks. Preliminary life cycle assessment suggested that the environmental impacts of artificial turf fields were lower than equivalent grass fields. Areas that need further research to better understand and mitigate the potential negative environmental impacts of artificial turf are identified.

  View details for DOI 10.1021/es4044193

  View details for Web of Science ID 000331774100005

  View details for PubMedID 24467230

• Chloroform Hydrodechlorination Behavior of Alumina-supported Pd and PdAu Catalysts AICHE JOURNAL Velazquez, J. C., Leekumjorn, S., Nguyen, Q. X., Fang, Y., Heck, K. N., Hopkins, G. D., Reinhard, M., Wong, M. S. 2013; 59 (12): 4474-4482

  View details for DOI 10.1002/aic.14250

  View details for Web of Science ID 000330039200004

• Critical Review of Desalination Concentrate Management, Treatment and Beneficial Use ENVIRONMENTAL ENGINEERING SCIENCE Xu, P., Cath, T. Y., Robertson, A. P., Reinhard, M., Leckie, J. O., Drewes, J. E. 2013; 30 (8): 502-514

  View details for DOI 10.1089/ees.2012.0348

  View details for Web of Science ID 000323206400008

• Rate laws and kinetic modeling of N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE) transformation by hydroxyl radical in aqueous solution WATER RESEARCH Tung Viet Nguyen, T. V., Reinhard, M., Gin, K. Y. 2013; 47 (7): 2241-2250

  View details for DOI 10.1016/j.watres.2013.01.047

  View details for Web of Science ID 000317699900013

• Effects of Chlorine Exposure Conditions on Physiochemical Properties and Performance of a Polyamide Membrane-Mechanisms and Implications ENVIRONMENTAL SCIENCE & TECHNOLOGY Van Thanh Do, V. T., Tang, C. Y., Reinhard, M., Leckie, J. O. 2012; 46 (24): 13184-13192

  View details for DOI 10.1021/es302867f

  View details for Web of Science ID 000312432200021

• Recycled water for stream flow augmentation: Benefits, challenges, and the presence of wastewater-derived organic compounds SCIENCE OF THE TOTAL ENVIRONMENT Plumlee, M. H., Gurr, C. J., Reinhard, M. 2012; 438: 541-548

  Abstract

  Stream flow augmentation with recycled water has the potential to improve stream habitat and increase potable water supply, but the practice is not yet well understood or documented. The objectives of this report are to present a short review illustrated by a case study, followed by recommendations for future stream flow augmentation projects. Despite the fact that wastewater discharge to streams is commonplace, a water agency pursuing stream flow augmentation with recycled water will face unique challenges. For example, recycled water typically contains trace amounts of organic wastewater-derived compounds (OWCs) for which the potential ecological risks must be balanced against the benefits of an augmentation project. Successful stream flow augmentation with recycled water requires that the lead agency clearly articulate a strong project rationale and identify key benefits. It must be assumed that the public will have some concerns about water quality. Public acceptance may be better if an augmentation project has co-benefits beyond maintaining stream ecosystems, such as improving water system supply and reliability (i.e. potable use offset). Regulatory or project-specific criteria (acceptable concentrations of priority OWCs) would enable assessment of ecosystem impacts and demonstration of practitioner compliance. Additional treatment (natural or engineered) of the recycled water may be considered. If it is not deemed necessary or feasible, existing recycled water quality may be adequate to achieve project goals depending on project rationale, site and water quality evaluation, and public acceptance.

  View details for DOI 10.1016/j.scitotenv.2012.08.062

  View details for Web of Science ID 000313155300060

  View details for PubMedID 23041295

• Effects of hypochlorous acid exposure on the rejection of salt, polyethylene glycols, boron and arsenic(V) by nanofiltration and reverse osmosis membranes WATER RESEARCH Van Thanh Do, V. T., Tang, C. Y., Reinhard, M., Leckie, J. O. 2012; 46 (16): 5217-5223

  View details for DOI 10.1016/j.watres.2012.06.044

  View details for Web of Science ID 000309095800030

• Effects of hypochlorous acid exposure on the rejection of salt, polyethylene glycols, boron and arsenic(V) by nanofiltration and reverse osmosis membranes. Water research Do, V. T., Tang, C. Y., Reinhard, M., Leckie, J. O. 2012; 46 (16): 5217-5223

  Abstract

  The separation layer of polyamide-based (PA) thin film composite (TFC) membranes can be modified by active chlorine species. The PA-TFC membranes, NF90, BW30 and NF270, were exposed to different concentrations of sodium hypochlorite (NaOCl) at pH 5 for 24 h. Elemental composition obtained from X-ray Photoelectron Spectroscopy (XPS) showed that the chlorine content in the PA layer increased with the chlorine concentrations. Treatment of membranes with 10 ppm Cl increased the membrane hydrophilicity. By contrast, when treated with 1000 ppm Cl or more, the membranes became less hydrophilic. Water permeability values for all 3 membrane types declined with increased chlorine concentrations. Filtration of polyethylene glycols (PEGs) with molecular weights of 200, 400 and 600 Daltons (Da) was performed to investigate the influence of chlorine treatment on membrane molecular weight cut off (MWCO) and rejection by size exclusion. Treatment with 10 and 100 ppm Cl lowered the MWCO while treatment with higher concentrations increased the MWCO. All chlorinated membranes experienced higher NaCl rejection compared to virgin ones. The performance of NF90 was tested with respect to the rejection of inorganic contaminants including boron (H(3)BO(3)) and arsenic (H(2)AsO(4)(-)). The boron rejection results paralleled PEG rejection whereas those for arsenic followed NaCl rejection patterns. The changes in membrane performance due to chlorine treatment were explained in terms of competing mechanisms: membrane tightening, bond cleavage by N-chlorination and chlorination promoted polyamide hydrolysis.

  View details for DOI 10.1016/j.watres.2012.06.044

  View details for PubMedID 22818949

• Fate of Endocrine-Disrupting and Pharmaceutically Active Substances in Sand Columns Fed with Secondary Effluent JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE Ke, J., Gin, K. Y., Tan, L. H., Reinhard, M. 2012; 138 (10): 1067-1076

  View details for DOI 10.1061/(ASCE)EE.1943-7870.0000564

  View details for Web of Science ID 000312699100009

• Critical Review of Pd-Based Catalytic Treatment of Priority Contaminants in Water ENVIRONMENTAL SCIENCE & TECHNOLOGY Chaplin, B. P., Reinhard, M., Schneider, W. F., Schueth, C., Shapley, J. R., Strathmann, T. J., Werth, C. J. 2012; 46 (7): 3655-3670

  Abstract

  Catalytic reduction of water contaminants using palladium (Pd)-based catalysts and hydrogen gas as a reductant has been extensively studied at the bench-scale, but due to technical challenges it has only been limitedly applied at the field-scale. To motivate research that can overcome these technical challenges, this review critically analyzes the published research in the area of Pd-based catalytic reduction of priority drinking water contaminants (i.e., halogenated organics, oxyanions, and nitrosamines), and identifies key research areas that should be addressed. Specifically, the review summarizes the state of knowledge related to (1) proposed reaction pathways for important classes of contaminants, (2) rates of contaminant reduction with different catalyst formulations, (3) long-term sustainability of catalyst activity with respect to natural water foulants and regeneration strategies, and (4) technology applications. Critical barriers hindering implementation of the technology are related to catalyst activity (for some contaminants), stability, fouling, and regeneration. New developments overcoming these limitations will be needed for more extensive field-scale application of this technology.

  View details for DOI 10.1021/es204087q

  View details for Web of Science ID 000302850400012

  View details for PubMedID 22369144

• Degradation of Polyamide Nanofiltration and Reverse Osmosis Membranes by Hypochlorite ENVIRONMENTAL SCIENCE & TECHNOLOGY Van Thanh Do, V. T., Tang, C. Y., Reinhard, M., Leckie, J. O. 2012; 46 (2): 852-859

  Abstract

  The degradation of polyamide (PA) nanofiltration and reverse osmosis membranes by chlorine needs to be understood in order to develop chlorine-resistant membranes. Coated and uncoated fully aromatic (FA) and piperazine (PIP) semi-aromatic PA membranes were treated with hypochlorite solution and analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). XPS results showed that in chlorine treated FA PA membranes the ratio of bound chlorine to surface nitrogen was 1:1 whereas it was only 1:6 in the case of PIP PA membranes. Surface oxygen of uncoated FA and PIP membranes increased with increasing hypochlorite concentration whereas it decreased for coated FA membranes. High resolution XPS data support that chlorination increased the number of carboxylic groups on the PA surface, which appear to form by hydrolysis of the amide bonds (C(O)-N). FTIR data indicated the disappearance of the amide II band (1541 cm(-1)) and aromatic amide peak (1609 cm(-1)) in both coated and uncoated chlorinated FA membranes, consistent with the N-chlorination suggested by the XPS results. Furthermore, the surface charge of chlorinated membranes at low pH (<6) became negative, consistent with amide-nitrogen chlorination. Chlorination appeared to both increase and decrease membrane hydrophobicity depending on chlorination exposure conditions, which implied that N-chlorination and hydrolysis may be competing processes. The effects of property changes on the membrane performance were also observed for NF90, BW30, and NF270 membranes.

  View details for DOI 10.1021/es203090y

  View details for Web of Science ID 000299136200038

  View details for PubMedID 22221176

• Occurrence, fate, and fluxes of perfluorochemicals (PFCs) in an urban catchment: Marina Reservoir, Singapore WATER SCIENCE AND TECHNOLOGY Nguyen, V. T., Gin, K. Y., Reinhard, M., Liu, C. 2012; 66 (11): 2439-2446

  Abstract

  A study was carried out to characterize the occurrence, sources and sinks of perfluorochemicals (PFCs) in the Marina Catchment and Reservoir, Singapore. Salinity depth profiles indicated the reservoir was stratified with lower layers consisting of sea water (salinity ranging from 32 to 35 g L(-1)) and a brackish surface layer containing approximately 14-65% seawater. The PFC mixture detected in catchment waters contained perfluoroalkyl carboxylates (PFCAs), particularly perfluorooctanoate (PFOA), perfluorohexanoate (PFHpA), perfluorooctane sulfonate (PFOS) and PFC transformation products. PFC concentrations in storm runoff were generally higher than those in dry weather flow of canals and rivers. PFC concentration profiles measured during storm events indicated 'first flush' behavior, probably because storm water is leaching PFC compounds from non-point sources present in the catchment area. Storm runoff carries high concentrations of suspended solids (SS), which suggests that PFC transport is via SS. In Marina Bay, PFCs are deposited in the sediments along with the SS. In sediments, the total PFC concentration was 4,700 ng kg(-1), approximately 200 times higher than in the bottom water layers. Total perfluoroalkyl sulfonates (PFSAs), particularly PFOS and 6:2 fluoro telomer sulfonate (6:2 FtS) were dominant PFCs in the sediments. PFC sorption by sediments varied with perfluorocarbon chain length, type of functional group and sediment characteristics. A first approximation analysis based on SS transport suggested that the annual PFC input into the reservoir was approximately 35 ± 12 kg y(-1). Contributions of SS, dry weather flow of river/canals, and rainfall were approximately 70, 25 and 5%, respectively. This information will be useful for improving strategies to protect the reservoir from PFC contamination.

  View details for DOI 10.2166/wst.2012.475

  View details for Web of Science ID 000312239400023

  View details for PubMedID 23032776

• Novel Perspectives on the Bioaccumulation of PFCs - the Concentration Dependency ENVIRONMENTAL SCIENCE & TECHNOLOGY Liu, C., Gin, K. Y., Chang, V. W., Goh, B. P., Reinhard, M. 2011; 45 (22): 9758-9764

  Abstract

  The effects of exposure concentration on the bioaccumulation of four perfluorinated chemicals (PFCs): perfluorooctanesulfonate (PFOS), perfluoroocanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), was investigated using green mussels, Perna viridis. Mussels were exposed to concentrations of 1 μgL(-1) and 10 μgL(-1) of each PFC for 56 days, and the bioaccumulation factors (BAF) were found to range from 15 to 859 L/kg and from 12 to 473 L/kg at 1 μgL(-1) and 10 μgL(-1), respectively. For all compounds, the BAF was larger at the lower dosage. Results suggest that the bioaccumulation of PFCs is concentration dependent. This concentration dependency can be explained by a nonlinear adsorption mechanism, which was further supported by the experimental results. The sensitivity of BAF to exposure concentration was found to be positively related to perfluorinated chain length and the binding affinity of the compounds. Bioaccumulation of long chain carboxylates and sulfonates are more easily affected by concentration changes. The validity of the conventional kinetic method was examined by comparing the results with the fundamental steady-state method: in addition to the above-mentioned batch test, mussels were also subject to 24-day exposure (1 μgL(-1) and 10 μgL(-1)) followed by 24-day depuration. Contradictions were found in the resulting kinetic BAF and model curving fittings. A new kinetic model based on adsorption mechanism was proposed, which potentially provide more accurate description of the bioaccumulation process of PFCs.

  View details for DOI 10.1021/es202078n

  View details for Web of Science ID 000296756500039

  View details for PubMedID 21988464

• Photodegradation kinetics of p-tert-octylphenol, 4-tert-octylphenoxy-acetic acid and ibuprofen under simulated solar conditions in surface water CHEMOSPHERE Xu, Y., Tung Viet Nguyen, T. V., Reinhard, M., Gin, K. Y. 2011; 85 (5): 790-796

  Abstract

  Direct and indirect (sensitized) photolysis of p-tert-octylphenol (OP), 4-octylphenoxy-acetic acid (OP1EC), and ibuprofen (IBU) were investigated in laboratory water and surface water under simulated and natural sunlight conditions. Photodegradation obeyed apparent-first order kinetics with rates increasing in the presence of NO₂⁻, NO₃⁻, and humic acid (HAC). The bimolecular rate constants, k″, were determined for the reactions of OP and OP1EC with hydroxyl radical (·OH) using photolyzed hydrogen peroxide (H₂O₂) as the hydroxyl radical (·OH) and IBU as the reference compound. The k″ values for OP and OP1EC were (average and standard deviation) (10.9 ± 0.5) × 10⁹ M⁻¹ s⁻¹ and (8.6 ± 0.5) × 10⁹ M⁻¹ s⁻¹, respectively. Direct photolysis of OP is small with a quantum yield of 0.015 in the range of 285-295 nm. Based on laboratory and average solar intensity data, the estimated half-life of OP in different Singapore surface waters was estimated to range from 0.6 to 2.5d. The steady state hydroxyl radical concentration ([·OH](ss)) was estimated using a kinetic model that considered dissolved organic carbon compounds (DOC), nitrate, and nitrite as ·OH sources, and DOC, CO₃²⁻ and HCO₃⁻ as scavengers. In surface waters containing DOC 2.3-6.5 mg L⁻¹, nitrate 0-3.2 mg L⁻¹, and nitrite 0-2.5 mg L⁻¹, the calculated [·OH](ss) ranged from 5.2 × 10⁻¹⁵ to 9.6 × 10⁻¹⁵ M. Half-lives calculations based on this model underestimated the measured half-life by a factor of approximately 4.2 to 1.1. DOC was predicted to be the most important sensitizer except in a sample that contained relatively high nitrate and nitrite. In the presence of NO₃⁻, photoreactions produced nitrated OP and IBU. A mechanism for OP photolysis in the presence of nitrate is proposed.

  View details for DOI 10.1016/j.chemosphere.2011.06.069

  View details for Web of Science ID 000297959600013

  View details for PubMedID 21745677

• Occurrence of emerging organic contaminants in a tropical urban catchment in Singapore CHEMOSPHERE Xu, Y., Luo, F., Pal, A., Gin, K. Y., Reinhard, M. 2011; 83 (7): 963-969

  Abstract

  Emerging organic contaminants (EOCs) occurring in urban runoff can negatively impact sensitive ecosystems and drinking water resources. The occurrence of 13 EOCs was characterized in the Marina Catchment, a large urban catchment approximately one-sixth the area of Singapore. The 13 EOCs included alkylphenol ethoxylate metabolites (APEMs), hormones, pharmaceuticals, bisphenol A, and a pesticide (fipronil). The APEMs were most prevalent with concentrations of nonylphenol ethoxyacetic acid (NP1EC) and nonlyphenol (NP) ranging from several ng L(-1) to 6 μg L(-1) and 4 μg L(-1), respectively, while concentrations of octylphenol ethoxyacetic acid (OP1EC), dicarboxylated alkylphenol ethoxyacetic acid (CA3P1EC, CA4P1EC) were as high as 0.9 μg L(-1). Other EOCs were present in the ng L(-1) range: chloramphenicol 1-15 ng L(-1), ibuprofen 2-76 ng L(-1), naproxen 8-108 ng L(-1), bisphenol A 30-625 ng L(-1), fipronil 1-72 ng L(-1), estrone 1-304 ng L(-1), estriol 3-451 ng L(-1). The APEMs and EOCs detected appear to enter canals and rivers from non-point sources, possibly from runoff and leaking sewer lines. The closure of Marina Bay with a barrage has resulted in significantly higher levels of APEMS compared to when the bay was open to the sea. Depth profiles show that NP1EC and OP1EC were notably lower in deep waters compared to surface waters. NP, estrone and estriol exceeded literature-based Predicted No Effect Concentration (PNEC) values.

  View details for DOI 10.1016/j.chemosphere.2011.02.029

  View details for Web of Science ID 000290507800011

  View details for PubMedID 21392814

• Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes JOURNAL OF MEMBRANE SCIENCE Louie, J. S., Pinnau, I., Reinhard, M. 2011; 367 (1-2): 249-255

  View details for DOI 10.1016/j.memsci.2010.10.067

  View details for Web of Science ID 000286852000031

• Occurrence and source characterization of perfluorochemicals in an urban watershed CHEMOSPHERE Nguyen, V. T., Reinhard, M., Karina, G. Y. 2011; 82 (9): 1277-1285

  Abstract

  Perfluorochemicals (PFCs) are used in numerous applications, mainly as surfactants, and occur ubiquitously in the environment as complex mixtures. This study was undertaken to characterize the occurrence and sources of commonly detected PFC compounds in surface waters of the Marina catchment, a watershed that drains an urbanized section of Singapore. Of the 19 target PFCs, 13 were detected with perfluorooctanoic acid (PFOA) (5-31 ng L(-1)) and perfluorooctane sulfonate (PFOS) (1-156 ng L(-1)) being the dominant components. Other compounds detected included perfluoroalkyl carboxylates (C7-C12) and perfluoroalkyl sulfonates (C6 and C8). Sulfonamide compounds detected 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA), 2-(N-methylperfluorooctanesulfonamido) acetic acid (N-MeFOSAA), perfluorooctanesulfonamido acetic acid (FOSAA) and perfluorooctanesulfonamide (FOSA) were putative transformation products of N-EtFOSE and N-MeFOSE, the N-ethylated and N-methylated ethyl alcohol derivatives, respectively. Surface water concentrations were generally higher during dry weather than during storm water flow: the median concentrations of total PFCs in dry and wet weather were 57 and 138 ng L(-1) compared to 42 and 79 ng L(-1), respectively, at Stamford and Alexandra canal, suggesting the presence of a continuous source(s) which is subject to dilution during storm events. In rain water, median concentrations were 6.4 ng L(-1), suggesting rain contributed from 12-25% to the total PFC load for non-point source sites. The longitudinal concentration profile along one of the canals revealed a point source of sulfonated PFCs (PFOS), believed to originate from aqueous film-forming foam (AFFF). Sources were characterized using principal component analysis (PCA) and by plotting PFHxS/PFOA against PFOS/PFOA. Typical surface waters exhibit PFOS/PFOA and PFHxS/PFOA ratios below 0.9 and 0.5, respectively. PCA plots reveal waters impacted by "non-typical" PFC sources in Alexandra canal.

  View details for DOI 10.1016/j.chemosphere.2010.12.030

  View details for Web of Science ID 000287563200009

  View details for PubMedID 21208640

• Biotransformation of Halogenated Nonylphenols with Sphingobium Xenophagum Bayram and a Nonylphenol-Degrading Soil-Enrichment Culture ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY Li, Y., Montgomery-Brown, J., Reinhard, M. 2011; 60 (2): 212-219

  Abstract

  When discharged in chlorinated wastewater, alkylphenol ethoxylate metabolites (APEMs) are often discharged in halogenated form (XAPEMs, X = Cl, or Br). The potential environmental impact of XAPEM release was assessed by studying the biotransformation of halogenated nonylphenol by Sphingobium xenophagum Bayram and a soil-enrichment culture. S. xenophagum Bayram transformed chlorinated nonylphenol (ClNP) slowly and nearly completely to form nonyl alcohol; the monobrominated nonylphenol (BrNP) and dibrominated nonylphenol were transformed cometabolically with nonylphenol (NP) as the primary substrate. The presence of either ClNP or BrNP in the S. xenophagum Bayram cultures retarded the transformation of nonhalogenated NP. NP-degrading soil cultures transformed nonhalogenated NP to a mixture of nonyl alcohols but were not capable of transforming either ClNP or BrNP. The presence of either ClNP or BrNP retarded the transformation of nonhalogenated NP in the soil cultures, as was observed in S. xenophagum Bayram cultures. Predicting the environmental fate of alkylphenol ethoxylate residues requires considering APEM halogenation during effluent chlorination and inhibitory effects as well as the refractory nature of halogenated metabolites.

  View details for DOI 10.1007/s00244-010-9576-4

  View details for Web of Science ID 000286601100003

  View details for PubMedID 20677004

• Impacts of emerging organic contaminants on freshwater resources: Review of recent occurrences, sources, fate and effects SCIENCE OF THE TOTAL ENVIRONMENT Pal, A., Gin, K. Y., Lin, A. Y., Reinhard, M. 2010; 408 (24): 6062-6069

  Abstract

  Rapid urbanization and frequent disposal of wastewater to surface water cause widespread contamination of freshwater supplies with emerging contaminants, such as pharmaceuticals, insecticides, surfactants, endocrine disruptors, including hormones. Although these organic contaminants may be present at trace levels, their adverse effects on aquatic life, animals and even humans are a growing concern. Numerous studies have been published on the occurrence and fate of emerging organic contaminants in different parts of the world, spanning a wide range of sources and aquatic environments including freshwater catchments, effluent wastewater streams, lakes, rivers, reservoirs, estuaries and marine waters. This paper reviews recent studies on the occurrence and fate of frequently detected pharmaceuticals and hormones and identifies areas that merit further research.

  View details for DOI 10.1016/j.scitotenv.2010.09.026

  View details for Web of Science ID 000285070800002

  View details for PubMedID 20934204

• Characterization of isolated polyamide thin films of RO and NF membranes using novel TEM techniques JOURNAL OF MEMBRANE SCIENCE Pacheco, F. A., Pinnau, I., Reinhard, M., Leckie, J. O. 2010; 358 (1-2): 51-59

  View details for DOI 10.1016/j.memsci.2010.04.032

  View details for Web of Science ID 000279277400007

• In-line gas chromatographic apparatus for measuring the hydrophobic micropore volume (HMV) and contaminant transformation in mineral micropores JOURNAL OF HAZARDOUS MATERIALS Cheng, H., Reinhard, M. 2010; 179 (1-3): 596-603

  Abstract

  Desorption of hydrophobic organic compounds from micropores is characteristically slow compared to surface adsorption and partitioning. The slow-desorbing mass of a hydrophobic probe molecule can be used to calculate the hydrophobic micropore volume (HMV) of microporous solids. A gas chromatographic apparatus is described that allows characterization of the sorbed mass with respect to the desorption rate. The method is demonstrated using a dealuminated zeolite and an aquifer sand as the model and reference sorbents, respectively, and trichloroethylene (TCE) as the probe molecule. A glass column packed with the microporous sorbent is coupled directly to a gas chromatograph that is equipped with flame ionization and electron capture detectors. Sorption and desorption of TCE on the sorbent was measured by sampling the influent and effluent of the column using a combination of switching and injection valves. For geosorbents, the HMV is quantified based on Gurvitsch's rule from the mass of TCE desorbed at a rate that is characteristic for micropores. Instrumental requirements, design considerations, hardware details, detector calibration, performance, and data analysis are discussed along with applications. The method is novel and complements traditional vacuum gravimetric and piezometric techniques, which quantify the total pore volume under vacuum conditions. The HMV is more relevant than the total micropore volume for predicting the fate and transport of organic contaminants in the subsurface. Sorption in hydrophobic micropores strongly impacts the mobility of organic contaminants, and their chemical and biological transformations. The apparatus can serve as a tool for characterizing microporous solids and investigating contaminant-solid interactions.

  View details for DOI 10.1016/j.jhazmat.2010.03.045

  View details for Web of Science ID 000278626700082

  View details for PubMedID 20388581

• Occurrence of Herbicides and Pharmaceutical and Personal Care Products in Surface Water and Groundwater around Liberty Bay, Puget Sound, Washington Symposium on Emerging Trace Contaminants in Surface and Ground Water Generated from Waste Water and Solid Waste Application Dougherty, J. A., Swarzenski, P. W., Dinicola, R. S., Reinhard, M. AMER SOC AGRONOMY. 2010: 1173–80

  Abstract

  Organic contaminants, such as pharmaceuticals and personal care products (PPCPs), pose a risk to water quality and the health of ecosystems. This study was designed to determine if a coastal community lacking point sources, such as waste water treatment plant effluent, could release PPCPs, herbicides, and plasticizers at detectable levels to their surface water and groundwater. Research was conducted in Liberty Bay, an embayment within Puget Sound, where 70% of the population (-10,000) uses septic systems. Sampling included collection of groundwater and surface water with grab samples and the use of polar organic chemical integrative samplers (POCIS). We analyzed for a broad spectrum of 25 commonly used compounds, including PPCPs, herbicides, and a flame retardant. Twelve contaminants were detected at least once; only N,N-diethyl-meta-toluamide, caffeine, and mecoprop, a herbicide not attributed to septic systems, were detected in more than one grab sample. The use of POCIS was essential because contaminants were present at very low levels (nanograms), which is common for PPCPs in general, but particularly so in such a small community. The use of POCIS allowed the detection of five compounds that were not present in grab samples. Data suggest that the community is contaminating local water with PPCPs; this effect is likely to increase as the population and product usage increase. The results presented here are a first step toward assessing the transport of herbicides and PPCPs into this coastal system.

  View details for DOI 10.2134/jeq.2009.0189

  View details for Web of Science ID 000279514200006

  View details for PubMedID 20830904

• Effects of Sorption on the Rejection of Trace Organic Contaminants During Nanofiltration ENVIRONMENTAL SCIENCE & TECHNOLOGY Steinle-Darling, E., Litwiller, E., Reinhard, M. 2010; 44 (7): 2592-2598

  Abstract

  Understanding the removal of trace organic contaminants is critical for membrane applications in water recycling. This study investigates the relationship between trace contaminant sorption and their rejection by nanofiltration (NF) membranes. A mass balance is developed that quantitatively links the rejection decline over time seen with some sorbing compounds to the total mass found sorbed on the membrane. The sorbed mass of perfluorooctane sulfonamide (FOSA) and fluoxetine evaluated from the mass balance agreed to within approximately 30% of the quantity analytically determined via extraction. Static sorption experiments show that sorption takes place predominantly within the polyamide separating layer of the membrane. Finally, the relationship between the steady-state rejection and sorption tendency of ten trace organic compounds is elucidated. A greater tendency to sorb results in lower steady-state rejection, both when comparing compounds of similar size, as well as when comparing the same compound under different conditions. As a result, a major finding is that in the presence of competitive sorption, that is, the presence of other trace organic compounds in the membrane matrix, some compounds sorb less and are therefore rejected more than when these compounds are alone in the feed. At no point during experimentation was any effect on the water flux observed.

  View details for DOI 10.1021/es902846m

  View details for Web of Science ID 000275993700057

  View details for PubMedID 20218539

• Indirect Photolysis of Perfluorochemicals: Hydroxyl Radical-Initiated Oxidation of N-Ethyl Perfluorooctane Sulfonamido Acetate (N-EtFOSAA) and Other Perfluoroalkanesulfonamides ENVIRONMENTAL SCIENCE & TECHNOLOGY Plumlee, M. H., McNeill, K., Reinhard, M. 2009; 43 (10): 3662-3668

  Abstract

  Selected perfluorinated surfactants were irradiated in aqueous hydrogen peroxide solutions using artificial sunlight to study transformation under aquatic environmental conditions. Indirect photolysis mediated by hydroxyl radical was observed for N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE), N-ethyl perfluorooctane sulfonamido acetate (N-EtFOSAA), N-ethyl perfluorooctane sulfonamide (N-EtFOSA), and perfluorooctane sulfonamide acetate (FOSAA). An upper limitforthe bimolecular reaction rate constant for reaction of *OH and N-EtFOSAA was determined to be (1.7 +/- 0.7) x 10(9) M(-1)s(-1). A proposed reaction pathwayfor degradation of the parent perfluorochemical, N-EtFOSE, to the other perfluoroalkanesulfonamides and perfluorooctanoate (PFOA) was developed and includes oxidation and N-dealkylation steps. As they did not undergo additional degradation, perfluorooctane sulfonamide (FOSA) and PFOA were the final degradation products of hydroxyl radical-initiated oxidation. UV-visible absorption spectra for the perfluorochemicals, showing absorbance in the UV region below the range of natural sunlight are also reported. In sunlit environments, indirect photolysis of perfluorochemicals is likely to be important in the determination of their environmental fate given the slow rates expected for biotransformation and weak sorption. Photolytic conversion of perfluorochemicals into refractory perfluorinated acids, mainly PFOA, could mean that a significant fraction of these compounds will accumulate in the world's oceans.

  View details for DOI 10.1021/es803411w

  View details for Web of Science ID 000266046700043

  View details for PubMedID 19544870

• Controlled field studies on soil aquifer treatment in a constructed coastal sandfill WATER SCIENCE AND TECHNOLOGY Chua, L. H., Leong, M. C., Lo, E. Y., Reinhard, M., Robertson, A. P., Lim, T. T., Shuy, E. B., Tan, S. K. 2009; 60 (5): 1283-1293

  Abstract

  A controlled artificial recharge experiment was conducted to investigate the effect of soil aquifer treatment during percolation of secondary and tertiary (ultrafiltered) treated wastewater through the shallow vadoze zone of a newly constructed coastal sandfill. The sandfill is a reclaimed land constructed from marine sand dredged from the seabed. To obtain 1-D flow, a stainless steel column was driven to a depth of 2.5 m, penetrating the phreatic surface. Wastewater was percolated through the column under fully-saturated and unsaturated conditions. Infiltration rates, dissolved organic carbon (DOC) and ultra-violet absorption (UVA) were monitored. The wastewaters were recharged at similar infiltration rates of approximately 5.5 m/day and 3.5 m/day under fully-saturated and unsaturated conditions, respectively. In both cases, clogging occurred 40 days after the start of recharge, under saturated conditions. For secondary treated wastewater, DOC concentration (mg/l) reduced by 28% and 13% under unsaturated and saturated conditions, respectively. The corresponding UVA reduction was 19.4% and 14.1%. Similar reductions in DOC were observed for the tertiary treated wastewater; however, the reduction in UVA was higher; 28% and 22% under unsaturated and saturated conditions, respectively. On an mass removal (mg/m(2) DOC) basis, DOC reduction appeared to be more significant under unsaturated conditions. This is attributed to the presence of interstitial oxygen.

  View details for DOI 10.2166/wst.2009.408

  View details for Web of Science ID 000269551700021

  View details for PubMedID 19717916

• Gas and liquid permeation properties of modified interfacial composite reverse osmosis membranes JOURNAL OF MEMBRANE SCIENCE Louie, J. S., Pinnau, I., Reinhard, M. 2008; 325 (2): 793-800

  View details for DOI 10.1016/j.memsci.2008.09.006

  View details for Web of Science ID 000262946800036

• Implementing Heterogeneous Catalytic Dechlorination Technology for Remediating TCE-Contaminated Groundwater ENVIRONMENTAL SCIENCE & TECHNOLOGY Davie, M. G., Cheng, H., Hopkins, G. D., Lebron, C. A., Reinhard, M. 2008; 42 (23): 8908-8915

  Abstract

  To transition catalytic reductive dechlorination (CRD) into practice, it is necessary to demonstrate the effectiveness, robustness, and economic competitiveness of CRD-based treatment systems. A CRD system scaled up from previous laboratory studies was tested for remediating groundwater contaminated with 500-1200 microg L(-1) trichloroethylene (TCE) at Edwards Air Force Base (AFB), California. Groundwater was pumped from a treatment well at 2 gal min(-1), amended with hydrogen to 0.35 mg L(-1) and contacted for 2.3 min with 20 kg eggshell-coated Pd on alumina beads (2% Pd by wt) packed in a fixed-bed reactor, and then returned to the aquifer. Operation was continuous for 23 h followed a 1 h regeneration cycle. After regeneration, TCE removal was 99.8% for 4 to 9 h and then declined to 98.3% due to catalyst deactivation. The observed catalyst deactivation was tentatively attributed to formation of sulfidic compounds; modeling of catalyst deactivation kinetics suggests the presence of sulfidic species equivalent to 2-4 mg L(-1) hydrogen sulfide in the reactor water. Over the more than 100 day demonstration period, TCE concentrations in the treated groundwater were reduced by >99% to an average concentration of 4.1 microg L(-1). The results demonstrate CRD as a viable treatment alternative technically and economically competitive with activated carbon adsorption and other conventional physicochemical treatmenttechnologies.

  View details for DOI 10.1021/es8014919

  View details for Web of Science ID 000261307200051

  View details for PubMedID 19192817

• NP1EC degradation pathways under oxic and microxic conditions ENVIRONMENTAL SCIENCE & TECHNOLOGY Montgomery-Brown, J., Li, Y., Ding, W., Mong, G. M., Campbell, J. A., Reinhard, M. 2008; 42 (17): 6409-6414

  Abstract

  The degradation pathway of nonylphenol ethoxyacetic acid (NP1EC) and the conditions favoring dicarboxylated alklyphenol ethoxyacetic acid (CAnP1EC; where n = the number of aliphatic carbon atoms) formation were studied in oxic microcosms constructed with organic carbon-poor soil from the Mesa soil aquifer treatment (SAT) facility (Arizona) and pristine organic carbon-rich sediments from Coyote Creek (California). Results suggest that the availability of dissolved oxygen determines the dominant biodegradation pathway; ether cleavage and the formation of NP is favored by oxic conditions, while alkyl chain oxidation and the formation of CAP1ECs is favored under microxic conditions. In the Mesa microcosms, para-NP1EC was transformed to para-nonylphenol (NP) before being rapidly transformed to nonyl alcohols via ipso-hydroxylation. In the Coyote Creek microcosms, large quantities of CAP1ECs were observed. Initially, CA8P1ECs were the dominant metabolites, but as biodegradation continued, CAP1ECs became the dominant metabolites. Compared to the CAsP1ECs, the number of CA6P1ECs peaks observed was small (< 6) even though their concentrations were high. Several novel metabolites, tentatively identified as 3-alkylchroman-4-carboxylic acids (with alkyl groups ranging from C2 to C5), were formed in the Coyote Creek microcosms. These metabolites are presumably formed from ortho-CAP1ECs by intramolecular ring closure.

  View details for DOI 10.1021/es702561t

  View details for Web of Science ID 000258883300020

  View details for PubMedID 18800508

• Perfluorochemicals in water reuse CHEMOSPHERE Plumlee, M. H., Larabee, J., Reinhard, M. 2008; 72 (10): 1541-1547

  Abstract

  Faced with freshwater shortages, water authorities are increasingly utilizing wastewater reclamation to augment supplies. However, concerns over emerging trace contaminants that persist through wastewater treatment need to be addressed to evaluate potential risks. In the present study, perfluorinated surfactant residues were characterized in recycled water from four California wastewater treatment plants that employ tertiary treatment and one that treats primary sewage in a wetland constructed for both treatment and wildlife habitat. Effluent concentrations were compared with surface and groundwater from a creek where recycled water was evaluated as a potential means to augment flow (Upper Silver and Coyote Creeks, San Jose, CA). In the recycled water, 90-470 ng/l perfluorochemicals were detected, predominantly perfluorooctanoate (PFOA; 10-190 ng/l) and perfluorooctanesulfonate (PFOS; 20-190 ng/l). No significant removal of perfluorochemicals was observed in the wetland (total concentration ranged 100-170ng/l across various treatment stages); in this case, 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA), perfluorodecanesulfonate (PFDS), and PFOS were dominant. Though there is currently no wastewater discharge into the creeks, perfluorochemicals were found in the surface water and underlying groundwater at a total of 20-150 ng/l with PFOS and PFOA again making the largest contribution. With respect to ecotoxicological effects, perfluorochemical release via recycled water into sensitive ecosystems requires evaluation.

  View details for DOI 10.1016/j.chemosphere.2008.04.057

  View details for Web of Science ID 000259166200021

  View details for PubMedID 18547612

• Nanofiltration for trace organic contaminant removal: Structure, solution, and membrane fouling effects on the rejection of perfluorochemicals ENVIRONMENTAL SCIENCE & TECHNOLOGY Steinle-Darling, E., Reinhard, M. 2008; 42 (14): 5292-5297

  Abstract

  The use of nanofiltration (NF) membranes for water recycling requires an improved understanding of the factors that govern rejection of potentially harmful organic trace contaminants. Rejections of 15 perfluorochemicals (PFCs)--5 perfluorinated sulfonates, 9 perfluorinated carboxylates, and perfluorooctane sulfonamide (FOSA)--by four nanofiltration membranes (NF270, NF200, DK, and DL) were measured. Rejections for anionic species were >95% for MW >300 g/mol. FOSA (MW = 499 g/mol), which is uncharged at the pH of deionized water (5.6), was rejected as little as 42% (DL membrane). Decreasing the pH to less than 3 decreases rejection by up to 35%, effectively increasing the MWCO of NF270 by >200 g/mol, while a 2500 mg/L NaCl equivalent increase in ionic strength reduces rejections <1%. An alginate fouling layer increases transmission, where quantifiable, by factors of 4-8. Accumulation of PFCs on membranes was measured after the completion of rejection experiments. Based on rejection kinetics and the extent of sorption, we infer that two different sorption processes are significant: charged species adsorb quickly to the membrane surface, whereas the uncharged FOSA absorbs within the membrane matrix in a much slower process.

  View details for DOI 10.1021/es703207s

  View details for Web of Science ID 000257620000045

  View details for PubMedID 18754383

• Palladium-indium catalyzed reduction of N-nitrosodimethylamine: Indium as a promoter metal ENVIRONMENTAL SCIENCE & TECHNOLOGY Davie, M. G., Shih, K., Pacheco, F. A., Leckie, J. O., Reinhard, M. 2008; 42 (8): 3040-3046

  Abstract

  An emerging technology for the removal of N-nitrosodimethylamine (NDMA) from drinking and groundwater is reductive destruction using noble metal catalysts and hydrogen gas as a reducing agent. Bimetallic palladium-indium (Pd-In) supported on alumina combines the ability of Into activate NDMA with the hydrogen activating properties of Pd. This study examined the effect of In addition to a commercial 5% Pd by weight on gamma-Al2O3 catalyst on the efficacy of NDMA reduction. The pseudo-first-order rate constant increased proportionately to In loading from 0.057 h(-1) for 0% In to a maximum of 0.25 h(-1) for 1% In and then decreased with additional in loading. Data suggest that hydrogen activation occurred only on Pd surfaces and In activated NDMA 20 times more effectively than Pd on a mass basis. The rate-limiting factor was NDMA activation for In loadings below 1%. The decrease at higher loadings is interpreted as In blocking pore spaces and limiting access to Pd sites, suggesting monatomic hydrogen limitation. The only products detected were dimethylamine and ammonium with carbon and nitrogen balances in excess of 92%, consistent with a mechanism involving reductive N-N bond cleavage. Results from this study serve as a basis for optimizing bimetallic catalysts for treating NDMA contaminated waters.

  View details for DOI 10.1021/es7023115

  View details for Web of Science ID 000254890400059

  View details for PubMedID 18497163

• The rate of 2,2-dichloropropane transformation in mineral micropores: Implications of sorptive preservation for fate and transport of organic contaminants in the subsurface ENVIRONMENTAL SCIENCE & TECHNOLOGY Cheng, H., Reinhard, M. 2008; 42 (8): 2879-2885

  Abstract

  Nanometer scale pores are ubiquitous in porous geologic media (soils and sediments). Sorption of organic contaminants in micropores (< or = 2 nm) can inhibittheir hydrolytic transformation due to the limited availability of reactive water within hydrophobic micropore spaces. As a test case, we studied the dehydrohalogenation of 2,2-dichloropropane (2,2-DCP) sorbed in the micropores of several model mineral solids. In the micropores of a hydrophobic dealuminated Y zeolite, CBV-780, 2,2-DCP dehydrohalogenation proceeded significantly slower than in bulk aqueous solution and eventually stopped. This was attributed to the depletion of reactive water molecules in the micropore spaces. The 2,2-DCP sorbed in the micropores of more hydrophilic solids (aquifer sediment, aquifer sand, and silica gel) also transformed slower than in aqueous solution, and the reaction no longer followed first-order kinetics. Results of transport modeling support that reactive contaminants sorbed in microporous minerals can be preserved over geological time scales under conditions that limit desorption. This study shows that hydrophobic micropores in geological media may act as an important sink for anthropogenic organic contaminants in the subsurface, and that sorption in micropores may significantly increase the persistence of the sorbed contaminants.

  View details for DOI 10.1021/es702888h

  View details for Web of Science ID 000254890400034

  View details for PubMedID 18497138

• N-nitrosodimethylamine (NDMA) removal by reverse osmosis and UV treatment and analysis via LC-MS/MS WATER RESEARCH Plumlee, M. H., Lopez-Mesas, M., Heidlberger, A., Ishida, K. P., Reinhard, M. 2008; 42 (1-2): 347-355

  Abstract

  N-nitrosodimethylamine (NDMA) is a probable human carcinogen found in ng/l concentrations in chlorinated and chloraminated water. A method was developed for the determination of ng/l levels of NDMA using liquid chromatography-tandem mass spectrometry (LC-MS/MS) preceded by sample concentration via solid-phase extraction with activated charcoal. Recoveries were greater than 90% and allowed a method reporting limit as low as 2ng/l. Using this method, the removal of NDMA was determined for the Interim Water Purification Facility (IWPF), an advanced wastewater treatment facility operated by the Orange County Water District (OCWD) in Southern California. The facility treats effluent from an activated sludge treatment plant with microfiltration (MF), reverse osmosis (RO), and an ultraviolet-hydrogen peroxide advanced oxidation process (UV-AOP). Six nitrosamines were surveyed: NDMA, N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Only NDMA was detected and at all treatment steps in the IWPF, with influent concentrations ranging from 20 to 59 ng/l. Removals for RO and UV ranged from 24% to 56% and 43% to 66%, respectively. Overall, 69+/-7% of the original NDMA concentration was removed from the product water across the advanced treatment process and, in combination with blending, the final concentration did not exceed the California drinking water notification level of 10 ng/l. NDMA removal data are consistent with findings reviewed for other advanced treatment facilities and laboratory studies.

  View details for DOI 10.1016/j.watres.2007.07.022

  View details for Web of Science ID 000253045900034

  View details for PubMedID 17697696

• Evaluating the impacts of membrane type, coating, fouling, chemical properties and water chemistry on reverse osmosis rejection of seven nitrosoalklyamines, including NDMA WATER RESEARCH Steinle-Darling, E., Zedda, M., Plumlee, M. H., Ridgway, H. F., Reinhard, M. 2007; 41 (17): 3959-3967

  Abstract

  Reverse osmosis (RO) treatment has been found to be effective for a wide range of organics but generally small, polar, uncharged molecules such as N-nitrosodimethylamine (NDMA) can be poorly rejected. The rejection of seven N-nitrosoalkylamines with molecular masses in the range of 78-158Da, including NDMA, N-nitrosodiethylamine (NDEA), N-nitrosomethylethylamine (NMEA), N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip) by three commercial brackish-water reverse osmosis membranes was studied in flat-sheet cells under cross-flow conditions. The membranes used were ESPA3 (Hydranautics), LFC3 (Hydranautics) and BW-30 (Dow/Filmtec), commonly used in water reuse applications. The effects of varying ionic strength and pH, dip-coating membranes with PEBAX 1657, a hydrophilic polymer, and artificial fouling with alginate on nitrosamine rejection were quantified. Rejection in deionized (DI) water increased with molecular mass from 56 to 70% for NDMA, to 80-91% for NMEA, 89-97% for NPyr, 92-98% for NDEA, and to beyond the detection limits for NPip, NDPA and NDBA. For the nitrosamines with quantifiable transmission, linear correlations (r(2)>0.97) were found between the number of methyl groups and the log(transmission), with factor 0.35 to 0.55 decreases in transmission per added methyl group. A PEBAX coating lowered the ESPA3 rejection of NDMA by 11% but increased the LFC3 and BW30 rejection by 6% and 15%, respectively. Artificially fouling ESPA3 membrane coupons with 170g/m(2) alginate decreased the rejection of NDMA by 18%. A feed concentration of 100mM NaCl decreased rejection of NDMA by 15% and acidifying the DI water feed to pH=3 decreased the rejection by 5%, whereas increasing the pH to 10 did not have a significant (p<0.05) effect.

  View details for DOI 10.1016/j.watres.2007.05.034

  View details for Web of Science ID 000249967900018

  View details for PubMedID 17582457

• Photochemical attenuation of N-nitrosodimethylamine (NDMA) and other Nitrosamines in surface water ENVIRONMENTAL SCIENCE & TECHNOLOGY Plumlee, M. H., Reinhard, M. 2007; 41 (17): 6170-6176

  Abstract

  The aqueous photolysis of seven alkyl nitrosamines was studied by irradiation in a solar simulator. Nitrosamines included N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosodi-n-butylamine (NDBA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Direct photolysis at irradiations of 765 W/m2, representing Southern California midsummer, midday sun, resulted in half-lives of 16 min for NDMA and 12-15 min for the other nitrosamines. The quantum yield for NDMA was determined to be phi = 0.41 and phi = 0.43-0.61 for the other nitrosamines. Quantified products of NDMA photolysis included methylamine, dimethylamine, nitrite, nitrate, and formate, with nitrogen and carbon balances exceeding 98 and 79%, respectively. Indirect photolysis of nitrosamines in surface water was not observed; increasing dissolved organic carbon (DOC) slowed the NDMA photolysis rate because of light screening. Removal of NDMA measured in tertiary treated effluent flowing in a shallow, sunlit engineered channel agreed with photolysis rates predicted based on the measured quantum yield and system parameters. Because biodegradation is relatively slow, aquatic photolysis of NDMA is generally expected to be more significant even at relatively low levels of solar irradiation (t(1/2) = 8-38 h at 244-855 W/m2, 51 degrees N latitude, 1 m depth).

  View details for DOI 10.1021/es070818I

  View details for Web of Science ID 000249240100045

  View details for PubMedID 17937298

• Palladium-catalyzed aqueous hydrodehalogenation in column reactors: Modeling of deactivation kinetics with sulfide and comparison of regenerants APPLIED CATALYSIS B-ENVIRONMENTAL Munakata, N., Reinhard, M. 2007; 75 (1-2): 1-10

  View details for DOI 10.1016/j.apcatb.2007.03.005

  View details for Web of Science ID 000249223600001

• Potential for 17 beta-estradiol and estrone degradation in a recharge aquifer system JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE Lim, T. H., Gin, K. Y., Chow, S. S., Chen, Y. H., Reinhard, M., Tay, J. H. 2007; 133 (8): 819-826

  View details for DOI 10.1061/(ASCE)0733-9372(2007)133:8(919)

  View details for Web of Science ID 000248097500006

• Characterization of estrogen-degrading bacteria isolated from an artificial sandy aquifer with ultrafiltered secondary effluent as the medium APPLIED MICROBIOLOGY AND BIOTECHNOLOGY Ke, J., Zhuang, W., Gin, K. Y., Reinhard, M., Hoon, L. T., Tay, J. 2007; 75 (5): 1163-1171

  Abstract

  This study investigated the aerobic and anoxic biodegradation of four estrogens [estrone (E1), estradiol (E2), estriol (E3), and the synthetic 17 alpha-ethinylestradiol (EE2)] in microcosms constructed with marine sand and ulftrafiltered (UF) secondary effluent. Three estrogen-degrading bacteria, LHJ1, LHJ3, and CYH, were isolated. Based on gram-stain morphology and 16S rRNA sequence homology, LHJ1 and LHJ3 belong to the genus Acinetobacter and Agromyces, respectively; CYH matched to 95% with the genus Sphingomonas. Aerobically LHJ3 degrades E3, CYH degrades E1, and all three isolates oxidize E2 to E1. Under anoxic conditions, CYH degrades E1 and LHJ3 degrades E2, whereas E3 and EE2 were not degraded by the three isolates; EE2 was transformed in microcosms incubated with site ground water. The degradation kinetics of E1 and E2 by CYH and E2 by LHJ3 under aerobic conditions was linearly correlated with the initial concentration, which ranged from 50 to 2,000 microg/l. The degradation of E1 by CYH under anoxic conditions followed Michaelis-Menten kinetics. 16 alpha-Hydroxyestrone was found to be a transient transformation product of E3 under aerobic conditions.

  View details for DOI 10.1007/s00253-007-0923-y

  View details for Web of Science ID 000247255500026

  View details for PubMedID 17396255

• Sorption and inhibited dehydrohalogenation of 2,2-dichloropropane in micropores of dealuminated Y zeolites ENVIRONMENTAL SCIENCE & TECHNOLOGY Cheng, H., Reinhard, M. 2007; 41 (6): 1934-1941

  Abstract

  Contaminant transformation rates in the subsurface can be slowed by sorption onto geosorbents. We evaluated the effect of micropore sorption on contaminant transformation in a model system consisting of dealuminated Y zeolites and 2,2-dichloropropane (2,2-DCP). 2,2-DCP dehydrochlorinates in water to 2-chloropropene (2-CP) at a rate of 2.93 x 10(-4) min(-1) at 24 degrees C. The Y zeolites used range from hydrophilic (CBV-300) to hydrophobic (CBV-720 and CBV-780). Wet zeolite samples were loaded with 2,2-DCP at 24 degrees C and reacted at 50 degrees C for 10 h. Results show that the hydrophobic zeolites (CBV-720 and CBV-780) sorbed nearly 900 times more 2,2-DCP than the hydrophilic CBV-300 under wet conditions. 2,2-DCP transformed less when sorbed in micropores of CBV-720 (6.3%) and CBV-780 (5.0%) than in micropores of CBV-300 (81.5%), and significantly less than in water (> 99.85%). Inhibition in hydrophobic micropores is interpreted as lack of water solvating the transition state of 2,2-DCP dehydrohalogenation and the H+ and Cl- formed. Near the micropore openings, the transformation was relatively fast, consistent with greater abundance of water associated with the hydrophilic edge sites. These results indicate that in the subsurface the half-lives of reactive organic contaminants may be longer than predicted from bulk water data.

  View details for DOI 10.1021/es062332v

  View details for Web of Science ID 000244855100028

  View details for PubMedID 17410787

• Natural attenuation potential of downwelling streams for perfluorochemicals and other emerging contaminants WATER SCIENCE AND TECHNOLOGY Hoehn, E., Plumlee, M. H., Reinhard, M. 2007; 56 (11): 59-64

  Abstract

  Stream augmentation with tertiary treated municipal wastewater-i.e., recycled water-is increasingly considered as an ecologically beneficial way to utilize recycled water, especially in semi-arid regions of the American Southwest. There is concern that emerging contaminants, i.e. unregulated but biologically active organic compounds, may be present in recycled water and will impact on the aquatic environment and the underlying groundwater. Emerging contaminants include a wide variety of chemically disparate compounds, including pharmaceuticals, endocrine disruptors, and residues of perfluorochemical surfactants (PFCs). This paper presents background data on the occurrence and transport of PFC in Upper Silver Creek (USC) and Coyote Creek, in San Jose, California. USC feeds into Coyote Creek, which discharges into San Francisco Bay. Augmenting the natural flow of Coyote Creek with highly treated recycled water is currently being considered as a means to provide more freshwater to the river ecosystem. The reach of interest is approximately 1,000 m where USC flows on alluvial fan deposits. Data indicate that some PFCs are refractory.

  View details for DOI 10.2166/wst.2007.804

  View details for Web of Science ID 000253383500008

  View details for PubMedID 18057642

• Sorption of trichloroethylene in hydrophobic micropores of dealuminated Y zeolites and natural minerals ENVIRONMENTAL SCIENCE & TECHNOLOGY Cheng, H., Reinhard, M. 2006; 40 (24): 7694-7701

  Abstract

  Sorption of volatile organic compounds (VOCs) in low organic carbon (<0.1%) geosorbents is difficult to predict because the sorption capacity of the mineral matrix is poorly understood. This research demonstrates hydrophobic micropores can be important sorption sites for VOCs. We studied the sorption of water and TCE on three dealuminated Y zeolites ranging from hydrophilic (CBV-300) to hydrophobic (CBV-720 and CBV-780), with the surface cation density decreasing from 2.07 to 0.42 and 0.16 sites/ nm2, respectively. Water sorption and dehydration data indicate water affinity of the zeolite micropores decreases with micropore hydrophobicity. TCE sorption on the wet zeolites decreased with increasing surface cation density. At a relative pressure (P/P0) of 0.136, TCE filled only 0.034% of the micropore volume in wet CBV-300, but 16.9% and 18.6% in wet CBV-720 and CBV-780, respectively. TCE desorption data from dry and wet silica sand (Min-U-Sil 30), kaolinite (KGa-1), and smectite (SWy-1) confirmed VOC sorption in wet microporous minerals is controlled by both the micropore volume and hydrophobicity. Results suggestTCE adsorbs in hydrophobic micropores by displacing loosely bound water, consistent with the theoretical considerations indicating the process of transferring loosely bound water from hydrophobic micropores to the bulk phase is energetically favorable.

  View details for DOI 10.1021/es060886s

  View details for Web of Science ID 000242793400041

  View details for PubMedID 17256515

• Metal-catalyzed reduction of N-nitrosodimethylamine with hydrogen in water ENVIRONMENTAL SCIENCE & TECHNOLOGY Davie, M. G., Reinhard, M., Shapley, J. R. 2006; 40 (23): 7329-7335

  Abstract

  There is considerable need for the rapid destruction of N-nitrosodimethylamine (NDMA) in water because current alternative treatment methods are relatively inefficient. Powdered metal catalysts in conjunction with hydrogen gas showed notable potential for rapid destruction of N-nitrosodimethylamine (NDMA) in water. Palladium, copper-enhanced palladium, and nickel catalysts showed significant efficacy for NDMA reduction, with observed half-lives on the order of hours using 10 mg L(-1) catalyst metal. Other catalysts were screened because of their well-documented efficacy for reduction of halogenated hydrocarbons, including zerovalent iron, nickel-enhanced iron, nickel, and manganese. Starting with 100 microg L(-1) NDMA, a level observed at multiple field sites, pseudo-first-order kinetics were observed for all catalysts tested. No reaction intermediates were observed in any experiment; the amine group of NDMA was cleaved and reduced to dimethylamine with carbon balance in excess of 97%. Reductive catalysis may prove an efficient technology for mitigating the health risk posed by NDMA; this study provides the foundation for mechanistic and longevity research.

  View details for DOI 10.1021/es061097d

  View details for Web of Science ID 000242367100038

  View details for PubMedID 17180985

• Effects of polyether-polyamide block copolymer coating on performance and fouling of reverse osmosis membranes JOURNAL OF MEMBRANE SCIENCE Louie, J. S., Pinnau, I., Ciobanu, I., Ishida, K. P., Ng, A., Reinhard, M. 2006; 280 (1-2): 762-770

  View details for DOI 10.1016/j.memsci.2006.02.041

  View details for Web of Science ID 000239472900088

• Bioremediation of cis-DCE at a sulfidogenic site by amendment with propionate GROUND WATER MONITORING AND REMEDIATION Hoelen, T. P., Cunningham, J. A., Hopkins, G. D., Lebron, C. A., Reinhard, M. 2006; 26 (3): 82-91

  View details for Web of Science ID 000239636300007

• Natural attenuation of pharmaceuticals and alkylphenol polyethoxylate metabolites during river transport: Photochemical and biological transformation ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Lin, A. Y., Plumlee, M. H., Reinhard, M. 2006; 25 (6): 1458-1464

  Abstract

  The capacity of rivers to naturally attenuate trace organic compounds is an important but poorly understood process because the many factors that control attenuation are interrelated and difficult to study in isolation. To better understand the relative importance of chemical (photolysis and sorption) and biological attenuation processes, contaminant removal along a 12-km stretch of the Santa Ana River (SAR) was determined as a function of travel time, distance, and irradiance. Target contaminants included three pharmaceuticals (gemfibrozil, ibuprofen, and naproxen) and their metabolites, and the metabolites of alkylphenol polyethoxylates (APEMs). The APEMs included alkylphenols (APs), short-chain alkylphenol polyethoxylates (APEOs), alkylphenol polyethoxycarboxylates (APECs), and carboxyalkylphenol polyethoxycarboxylates (CAPECs). Overall removals ranged from 50% for APs to 100% for naproxen and increased with distance and time, in many cases following first-order kinetics. For naproxen, which is photolabile, average removals were 20 to 30% more during the day than at night; the nighttime and daytime half-lives were 3 h and 1.7 to 1.9 h, respectively. Comparison of field and laboratory data suggests that approximately 40% of the daytime naproxen removal can be attributed to photolysis with the remainder due to other processes, most likely sorption. For ibuprofen and gemfibrozil, half-lives were 5.4 and 2.7 h, respectively, and laboratory data suggest that biotransformation is the principal attenuating process. The APEM attenuation might be due to sorption and biotransformation; phototransformation may also play a minor role. These data demonstrate that travel times on the order of hours can significantly mitigate the impact of effluent discharge on the water quality of shallow rivers.

  View details for Web of Science ID 000240360300003

  View details for PubMedID 16764462

• EDTA, NTA, alkylphenol ethoxylate and DOC attenuation during soil aquifer treatment JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE Yoo, H. H., Miller, J. H., Lansey, K., Reinhard, M. 2006; 132 (6): 674-682

  View details for DOI 10.1061/(ASCE)0733-9372(2006)132:6(674)

  View details for Web of Science ID 000241779100013

• Measuring hydrophobic micropore volumes in geosorbents from trichloroethylene desorption data ENVIRONMENTAL SCIENCE & TECHNOLOGY Cheng, H., Reinhard, M. 2006; 40 (11): 3595-3602

  Abstract

  Hydrophobic micropores can play a significant role in controlling the long-term release of organic contaminants from geosorbents. We describe a technique for quantifying the total and the hydrophobic mineral micropore volumes based on the mass of trichloroethylene (TCE) sorbed in the slow-releasing pores under dry and wet conditions, respectively. Micropore desorption models were used to differentiate the fast- and slow-desorbing fractions in desorption profiles. The micropore environment in which organic molecules were sorbed in the presence of water was probed by studying the transformation of a water-reactive compound (2,2-dichloropropane or 2,2-DCP). For sediment from an alluvial aquifer, the total and hydrophobic micropore volumes estimated using this technique were 4.65 microL/g and 0.027 microL/g (0.58% of total), respectively. In microporous silica gel A, a hydrophobic micropore volume of 0.038 microL/g (0.035% of reported total) was measured. The dehydrohalogenation rate of 2,2-DCP sorbed in hydrophobic micropores of the sediment was slower than that reported in bulk water, indicating an environment of low water activity. The results suggest that hydrolyzable organic contaminants sorbed in hydrophobic micropores react slower than in bulk water, consistent with the reported persistence of reactive contaminants in natural soils.

  View details for DOI 10.1021/es0522581

  View details for Web of Science ID 000237921200030

  View details for PubMedID 16786699

• Harnessing natural attenuation of pharmaceuticals and hormones in rivers ENVIRONMENTAL SCIENCE & TECHNOLOGY Gurr, C. J., Reinhard, M. 2006; 40 (9): 2872-2876

  View details for Web of Science ID 000237251400011

  View details for PubMedID 16719085

• Reductive hydrodechlorination of trichloroethylene by palladium-on-alumina catalyst: C-13 solid-state NMR study of surface reaction precursors LANGMUIR Sriwatanapongse, W., Reinhard, M., Klug, C. A. 2006; 22 (9): 4158-4164

  Abstract

  Adsorption of trichloroethylene (TCE) on alumina-supported palladium catalysts (Pd/Al2O3) was studied in the presence and absence of hydrogen using 13C-solid state NMR. Carbon-13 NMR spectra indicate that at low coverage strongly adsorbed species are formed while at high coverage additional physisorbed species are present. Carbon-13 spin-echo amplitude data measured as a function of pulse separation, tau, was used to determine the 13C-13C intramolecular dipolar coupling and the carbon-carbon bond length of adsorbed species. Results indicate that a substantial fraction of the chemisorbed carbon species had undergone carbon-carbon bond scission forming single-carbon fragments, suggesting that the activation energy for carbon-carbon bond scission is comparable to the heat of adsorption. For the remaining surface species, the double bond is elongated to 1.46 +/- 0.03 A and is suspected to be chemically bonded ethynyl. At room temperature, adding an excess of hydrogen to catalyst that is covered to saturation with TCE precursors produces only in a small amount of ethane, indicating the fraction of surface species that are hydrodehalogenation precursors is small.

  View details for DOI 10.1021/la053087g

  View details for Web of Science ID 000236989300031

  View details for PubMedID 16618159

• Inhibition of 2,2-dichloropropane dehydrohalogenation by micropore sorption 231st National Meeting of the American-Chemical-Society Cheng, H., Reinhard, M. AMER CHEMICAL SOC. 2006

  View details for Web of Science ID 000238125904092

• In situ biotransformation of BTEX compounds under methanogenic conditions GROUND WATER MONITORING AND REMEDIATION Reinhard, M., Hopkins, G. D., Steinle-Darling, E., Lebron, C. A. 2005; 25 (4): 50-59

  View details for Web of Science ID 000233622800003

• Quantification of contaminant sorption-desorption time scales from batch experiments ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Cunningham, J. A., Deitsch, J. J., Smith, J. A., Reinhard, M. 2005; 24 (9): 2160-2166

  Abstract

  The ability to predict rates of contaminant sorption and desorption in the environment is essential in order to determine contaminant bioavailability, predict contaminant fate and transport, and assess risk. In this paper, we present a new method to determine sorption-desorption time scales from the temporal moments of batch experimental data. Here, the term time scale has a precise meaning: Time scales are defined in terms of the parameters of kinetic sorption models. The method can be implemented with either a diffusion-based model (t(diff) = a2/15D) or a linear-driving-force model (t(LDF) = I/k) for sorption kinetics and can be implemented with either a discrete or a continuous distribution of rate parameters. Three advantages to the new method are that the time scales t(diff) or t(LDF) can be calculated directly without best-fitting the experimental data, the calculated sorption-desorption time scales are not dependent on an arbitrarily chosen distribution (e.g., the commonly used gamma or lognormal distributions), and the time scales implied by the analysis are consistent with the time scale of the actual experiment. We apply the method to previously reported experiments of 1,2-dichlorobenzene (DCB) sorption onto four natural sorbents. Comparing the newly calculated sorption-desorption time scales to those reported previously indicates a different order for the four sorbents with regard to DCB sorption rate. Further applications and limitations of the method are discussed.

  View details for Web of Science ID 000231341300007

  View details for PubMedID 16193742

• Photodegradation of common environmental pharmaceuticals and estrogens in river water ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Lin, A. Y., Reinhard, M. 2005; 24 (6): 1303-1309

  Abstract

  Photodegradation rates of five pharmaceuticals (gemfibrozil, ibuprofen, ketoprofen, naproxen, and propranolol) and of four estrogens (estriol, estrone [E1], 17beta-estradiol [E2], and 17alpha-ethinylestradiol [EE2]), which are common contaminants in the aquatic environment, were measured in both purified and river water at environmentally relevant concentrations (1-2 microg/L) and different oxygen concentrations. Solutions were irradiated with a xenon arc lamp (765 W/m2; 290 nm < lambda < 700 nm) and analyzed using a high-performance liquid chromatography-tandem mass spectrometry method with electrospray ionization for pharmaceuticals and atmospheric pressure photoionization for estrogens. In river water, half-lives were 4.1 min [corrected] for ketoprofen, 1.1 h [corrected] for propranolol, 1.4 h for naproxen, 2 to 3 h for estrogens, and 15 h for gemfibrozil and ibuprofen. In air-saturated purified water, rates generally were slower except for that of ketoprofen, which reacted with a half-life of 2.5 min. Naproxen, propranolol, and E1 reacted with half-lives of 1.9, 4.4, and 4.7 h, respectively. The EE2, estriol, E2, gemfibrozil, and ibuprofen reacted with half-lives of 28.4, 38.2, 41.7, 91.4, and 205 h, respectively. The presence of oxygen doubled the direct photolysis rates of naproxen and propranolol. In nonautoclaved river water, 80% of E2 rapidly biotransformed to E1 within less than 20 min, whereas all other compounds remained stable over 22 h.

  View details for Web of Science ID 000229140400001

  View details for PubMedID 16117104

• Complete biological dehalogenation of chlorinated ethylenes in sulfate containing groundwater BIODEGRADATION Hoelen, T. P., Reinhard, M. 2004; 15 (6): 395-403

  Abstract

  The ability of dehalogenating bacteria to compete with sulfate reducing bacteria for electron donor was studied in microcosms that simulated groundwater contaminated with both chlorinated ethylenes and fuel hydrocarbon compounds. Results demonstrate that reductive dehalogenation of perchloroethylene to ethylene can proceed in the presence of > 100 mg l(-1) sulfate. The hydrogen concentration, which was 2.5 nM in the presence of approximately 150 mg l(-1) sulfate and in the absence of chlorinated compounds, decreased to 0.7 nM during the dechlorination of trichloroethylene and increased to 1.6 nM during the dechlorination of cis-dichloroethylene and vinyl chloride. With only sediment associated donor ("historical" donor) present, dechlorination of trichloroethylene proceeded slowly to ethylene (on a time scale of several years). Addition of toluene, a model hydrocarbon compound, stimulated dechlorination indirectly. Toluene degradation was rapid and linked to sulfate utilization, and presumably formed fermentable substrates that served as hydrogen donors. Dehalogenation was inhibited in soil free microcosms containing 5 mM sulfide, but inhibition was not observed when either aquifer sediment or 5 mM ferrous chloride was added.

  View details for Web of Science ID 000225103500006

  View details for PubMedID 15562997

• Hydraulics of recirculating well pairs for ground water remediation GROUND WATER Cunningham, J. A., Hoelen, T. P., Hopkins, G. D., Lebron, C. A., Reinhard, M. 2004; 42 (6): 880-889

  View details for Web of Science ID 000224850900011

• Hydraulics of recirculating well pairs for ground water remediation. Ground water Cunningham, J. A., Hoelen, T. P., Hopkins, G. D., Lebrón, C. A., Reinhard, M. 2004; 42 (6-7): 880-889

  Abstract

  Recirculating well pairs are a proven means of implementing bioremediation and may also be useful for applying other in situ ground water remediation technologies. A bromide tracer test was performed to characterize the hydraulic performance of a recirculating well pair installed at Moffett Field, California. In particular, we estimate two important properties of the recirculating well pair: (1) the fraction of captured water that is recycled between the wells, and (2) the travel-time distribution of ground water in the induced zone of recirculation. We also develop theoretical estimates of these two properties and demonstrate they depend upon a dimensionless pumping rate, denoted xi. The bromide breakthrough curve predicted from theory agrees well with that determined experimentally at Moffett Field. The minimum travel time between the wells is denoted t(min). In theory, t(min) depends inversely on Q, the pumping rate in the recirculating wells, and is proportional to a2, the square of the distance between the wells. Both the experimental and theoretical travel-time distributions indicate that at least half the recirculating water travels between the wells along fast flowpaths (travel time < 2*t(min)). Therefore, when designing recirculating well pairs, engineers should ensure that t(min) will be sufficiently high to allow biologically mediated reactions (or other in situ remediation processes) sufficient time to proceed.

  View details for PubMedID 15584301

• Occurrence and fate of pharmaceuticals and alkylphenol ethoxylate metabolites in an effluent-dominated river and wetland ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Gross, B., Montgomery-Brown, J., Naumann, A., Reinhard, M. 2004; 23 (9): 2074-2083

  Abstract

  The occurrence of pharmaceuticals, nonylphenol ethoxylate metabolites, and other wastewater-derived contaminants in surface waters is a potential environmental concern, especially since the discovery of contaminants with endocrine-disrupting properties. The present study investigated the discharge of emerging contaminants into the Santa Ana River (CA, USA) and their attenuation during river transport and passage through a constructed wetland. Contaminants studied included pharmaceuticals (gemfibrozil, ibuprofen, naproxen, ketoprofen, and carbamazepine) and their metabolites, hormones, the metabolites of alkylphenol polyethoxylates (APEMs), N-butyl benzenesulfonamide (NBBS), and chlorinated tris-propylphosphates (TCPPs). The APEMs included alkylphenols (APs), short-chain AP polyethoxylates (APEOs), AP polyethoxycarboxylates (APECs), and carboxylated APECs (CAPECs). In wastewater treatment plant effluent, APECs and CAPECs represented the dominant APEM fraction (1.8-18.7 microg/L), whereas APEOs and APs contributed only small amounts to the overall APEM concentrations (0.10-0.92 and < or =0.1 microg/L, respectively) except where the effluent was infiltrated into soil (5.2 microg/L). In effluents, ibuprofen and its metabolites, TCPPs, and NBBS were detected regularly (<0.5 microg/L), and the other pharmaceuticals were detected occasionally. Transport in the Santa Ana River for 11 km resulted in the significant attenuation of all contaminants, from 67% for gemfibrozil to 100% for others. Wetland treatment (residence time, 2-4 d) resulted in partial removal of ibuprofen, gemfibrozil, and TCPPs and transformed APEOs to APECs.

  View details for Web of Science ID 000223239600004

  View details for PubMedID 15378981

• Behavior of alkylphenol polyethoxylate metabolites during soil aquifer treatment WATER RESEARCH Montgomery-Brown, J., Drewes, J. E., Fox, P., Reinhard, M. 2003; 37 (15): 3672-3681

  Abstract

  The attenuation of alkylphenol polyethoxylates (APEOs) metabolites was studied at a soil aquifer treatment (SAT) site located in Arizona, USA. Two parcels of water were monitored during infiltration; one parcel was predominantly oxic while the other was predominantly anoxic. In this study, only alkylphenol ethoxycarboxylates (APECs) and carboxyalkylphenol ethoxycarboxylates (CAPECs) were detected, no short-chained APEOs were observed-even under anoxic conditions. APEO metabolites were rapidly (<7 days) removed under both aerobic and anoxic conditions. In general, the length of the ethoxycarboxylate chain decreases with depth--at depths greater than 3m, only alkylphenoxy acetic acids (AP1ECs), carboxyalkylphenoxy acetic acids (CAP1ECs), and alkylphenols (APs) remain. Under aerobic conditions, octylphenol and nonylphenol concentrations decreased by approximately 80% (w/w) within 3m of the ground surface. Under anoxic conditions however, alkylphenol concentrations increased by approximately 200% during the first 1.5m and then decreased during the next 1.5m; overall, under anoxic conditions, alkylphenol concentrations increased by approximately 38% within 3m. During infiltration, APEC and CAPEC concentrations decrease by more than 95% within 3m of SAT. Alternate flooding and drying cycles appear to enhance overall APEO metabolite removal efficiencies.

  View details for DOI 10.1016/S0043-1354(03)00294-X

  View details for Web of Science ID 000184512300015

  View details for PubMedID 12867334

• Comparing microfiltration-reverse osmosis and soil-aquifer treatment for indirect potable reuse of water WATER RESEARCH Drewes, J. E., Reinhard, M., Fox, P. 2003; 37 (15): 3612-3621

  Abstract

  Microfiltration (MF) followed by reverse osmosis (RO) and soil-aquifer treatment (SAT) are the two principal technologies considered for indirect potable reuse of wastewater. This study, conducted at the Northwest Water Reclamation Plant, Mesa (Arizona), evaluated MF/RO and SAT (>6 months residence time) treated tertiary effluent with respect to organics removal. Effluent organic matter was characterized as total organic carbon (TOC), by UV absorbance (UVA), solid-state carbon-13 nuclear magnetic resonance spectroscopy, and size exclusion chromatography. Several trace organic micropollutants, including EDTA, NTA, and alkylphenolethoxylate residues, were analyzed by GC/MS. The study revealed that final TOC concentrations of MF/RO and SAT are 0.3 and 1.0 mgl(-1), respectively. Based on the characterization techniques used, the character of bulk organics present in final SAT water resembles the character of natural organic matter present in drinking water. Depending on the molecular weight cut-off, RO membranes can efficiently reject high molecular weight organic matter (characterized as humic and fulvic acids). However, approximately 40-50 percent of the remaining TOC in permeates consists of low molecular weight acids and neutrals representing a molecular weight range of approximately 500Da and less. In the SAT treated effluent, EDTA and APECs were removed to approximately 4.3 and 0.54 microg/l, respectively, but were below the detection limit in the MF/RO treated effluent.

  View details for DOI 10.1016/S0043-1354(03)00230-6

  View details for Web of Science ID 000184512300008

  View details for PubMedID 12867327

• Occurrence and behavior of alkylphenol polyethoxylates in the environment ENVIRONMENTAL ENGINEERING SCIENCE Montgomery-Brown, J., Reinhard, M. 2003; 20 (5): 471-486

  View details for Web of Science ID 000185340900007

• Comparison of rhodamine WT and bromide in the determination of hydraulic characteristics of constructed wetlands ECOLOGICAL ENGINEERING Lin, A. Y., Debroux, J. F., Cunningham, J. A., Reinhard, M. 2003; 20 (1): 75-88

  View details for DOI 10.1016/S0925-8574(03)00005-3

  View details for Web of Science ID 000183189400006

• From effluent to new water: Performance evaluation and quality assurance CHIMIA Reinhard, M., Montgomery-Brown, J., Louie, J. S., Gross, B. 2003; 57 (9): 561-566

  View details for Web of Science ID 000185845100014

• Emerging contaminants in tertiary treated wastewater R+D in Life Sciences Congress Reinhard, M., Gross, B., Hadeler, A. SWISS CHEMICAL SOC. 2003: 31–32

  View details for Web of Science ID 000181545000019

• Injection-extraction treatment well pairs: An alternative to permeable reactive barriers GROUND WATER Cunningham, J. A., Reinhard, M. 2002; 40 (6): 599-607

  Abstract

  Two of the biggest drawbacks of using permeable reactive barriers (PRBs) to treat contaminated ground water are the high capital cost of installation, particularly when the contaminated ground water is deep below ground surface, and the uncertainty of whether or not PRBs remain effective for the long time scales (e.g., decades) needed for many contaminant plumes. The use of an injection-extraction treatment well pair (IETWP) for capture and treatment of contaminated ground water can circumvent these difficulties, while still providing many of the same advantages offered by PRBs. In this paper, the hydraulics of IETWPs and PRBs are compared, focusing primarily on the width of the captured plume. It is demonstrated that IETWPs act as hydraulic barriers in a manner similar to PRBs, and that IETWPs provide excellent plume capture. A mathematical expression is presented for the plume capture width of an IETWP oriented perpendicular to the ground water flow direction in a homogeneous aquifer. Also discussed are other practical considerations that might determine whether an IETWP is better suited than a PRB for a particular contaminated site; these considerations include operating and maintenance costs, and the conditions under which an IETWP system can be used for in situ remediation.

  View details for Web of Science ID 000179187500006

  View details for PubMedID 12425347

• Enhanced in situ bioremediation of BTEX contaminated groundwater by combined injection of nitrate and sulfate ENVIRONMENTAL SCIENCE & TECHNOLOGY Cunningham, J. A., Rahme, H., Hopkins, G. D., LeBron, C., Reinhard, M. 2001; 35 (8): 1663-1670

  Abstract

  Enhancement of in situ anaerobic biodegradation of BTEX compounds was demonstrated at a petroleum-contaminated aquifer in Seal Beach, CA. Specifically, combined injection of nitrate and sulfate into the contaminated aquifer was used to accelerate BTEX removal as compared to remediation by natural attenuation. An array of multi-level sampling wells was used to monitor the evolution of the in situ spatial distributions of the electron acceptors and the BTEX compounds. Nitrate was utilized preferentially over sulfate and was completely consumed within a horizontal distance of 4-6 m from the injection well; sulfate reduction occurred in the region outside the denitrifying zone. By combining injection of both nitrate and sulfate, the total electron acceptor capacity was enhanced without violating practical considerations that limit the amount of nitrate or sulfate that can be added individually. Degradation of total xylene appears linked to sulfate utilization, indicating another advantage of combined injection versus injection of nitrate alone. Benzene degradation also appears to have been stimulated by the nitrate and sulfate injection close to the injection well but only toward the end of the 15-month demonstration. The results are consistent with the hypothesis that benzene can be biodegraded anaerobically after other preferentially degraded hydrocarbons have been removed.

  View details for Web of Science ID 000168099000017

  View details for PubMedID 11329718

• Pd-catalyzed TCE dechlorination in water: Effect of [H-2](aq) and H-2-utilizing competitive solutes on the TCE dechlorination rate and product distribution ENVIRONMENTAL SCIENCE & TECHNOLOGY Lowry, G. V., Reinhard, M. 2001; 35 (4): 696-702

  Abstract

  The aqueous-phase H2 concentration ([H2](aq)) and the presence of H2-utilizing competitive solutes affect TCE dechlorination efficiency in Pd-based in-well treatment reactors. The effect of [H2](aq) and H2-utilizing competing solutes (cis-DCE, trans-DCE, 1,1-DCE, dissolved oxygen (DO), nitrite, nitrate) on the TCE transformation rate and product distribution were evaluated using 100 mg/L of a powdered Pd-on-Al2O3 catalysts in batch reactors or 1.0 g of a 1.6-mm Pd-on-gamma-Al2O3 catalyst in column reactors. The TCE dechlorination rate constant decreased by 55% from 0.034 +/- 0.006 to 0.015 +/- 0.001 min-1 when the [H2](aq) decreased from 1000 to 100 microM and decreased sharply to 0.0007 +/- 0.0003 min-1 when the [H2](aq) decreased from 100 to 10 microM. Production of reactive chlorinated intermediates and C4-C6 radical coupling products increased with decreasing [H2](aq). At an [H2](aq) of 10 microM (P/Po = 0.01), DCE isomers and vinyl chloride accounted for as much as 9.8% of the TCE transformed at their maximum but disappeared thereafter, and C4-C6 radical coupling products accounted for as much as 18% of TCE transformed. The TCE transformation rate was unaffected by the presence of cis-DCE (202 microM), trans-DCE (89 microM), and 1,1-DCE (91 microM), indicating that these compounds do not compete with TCE for catalyst active sites. DO is twice as reactive as TCE but had no effect on TCE conversion in the column below a concentration of 370 microM (11.8 mg/L), indicating that DO and TCE will not compete for active catalyst sites at typical groundwater DO concentrations. TCE conversion in the column was reduced by as much as a factor of 10 at influent DO levels greater than 450 mM (14.3 mg/L) because the [H2](aq) fell below 100 microM due to H2 utilized in DO conversion. Nitrite reacts 2-5 times slower than TCE and reduced TCE conversion by less than 4% at a concentration of 6630 microM (305 mg/L). Nitrate was not reactive and did not effect TCE conversion at a concentration of 1290 microM (80 mg/L).

  View details for Web of Science ID 000166990800009

  View details for PubMedID 11349280

• Coupling of toluene oxidation with PCE dechlorination under sulfidogenic conditions 6th International In Situ and On-Site Bioremediation Symposium Hoelen, T. P., Cunningham, J., Lebron, C. A., Reinhard, M. BATTELLE PRESS. 2001: 95–102

  View details for Web of Science ID 000175097900012

• Characterization of a nitrogen-containing octylphenol ethoxylate metabolite by chemical derivatization and degradation in combination with mass spectrometry INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY Fujita, Y., Campbell, J. A., Mong, G. M., Reinhard, M. 2001; 81 (1): 41-54

  View details for Web of Science ID 000172850400004

• Tailoring catalysts for hydrodechlorinating chlorinated hydrocarbon contaminants in groundwater APPLIED CATALYSIS B-ENVIRONMENTAL Schuth, C., Disser, S., Schuth, F., Reinhard, M. 2000; 28 (3-4): 147-152

  View details for Web of Science ID 000166227300001

• Binary desorption isotherms of TCE and PCE from silica gel and natural solids ENVIRONMENTAL SCIENCE & TECHNOLOGY Schaefer, C. E., Schuth, C., Werth, C. R., Reinhard, M. 2000; 34 (20): 4341-4347

  View details for Web of Science ID 000089970000013

• Pd-catalyzed TCE dechlorination in groundwater: Solute effects, biological control, and oxidative catalyst regeneration ENVIRONMENTAL SCIENCE & TECHNOLOGY Lowry, G. V., Reinhard, M. 2000; 34 (15): 3217-3223

  View details for Web of Science ID 000088561100040

• Behavior of (selected) alkylphenol ethoxycarboxylates (APECs), EDTA, and NTA in the vadose zone beneath recharge basins during soil aquifer treatment (SAT). Yoo, H. S., Debroux, J., Orwin, E., Fujita, Y., Reinhard, M. AMER CHEMICAL SOC. 2000: U621–U621

  View details for Web of Science ID 000087246103362

• Enhanced anaerobic bioremediation of groundwater contaminated by fuel hydrocarbons at Seal Beach, California BIODEGRADATION Cunningham, J. A., Hopkins, G. D., Lebron, C. A., Reinhard, M. 2000; 11 (2-3): 159-170

  Abstract

  Enhanced anaerobic biodegradation of groundwater contaminated by fuel hydrocarbons has been evaluated at a field experiment conducted at the Naval Weapons Station, Seal Beach, California. This experiment included the establishment of three different remediation zones in situ: one zone was augmented with sulfate, one was augmented with sulfate and nitrate, and the third was unaugmented. This enables a comparison of hydrocarbon biodegradation under sulfate-reducing, sequential denitrifying/sulfate-reducing, and methanogenic conditions, respectively. In general, the results from the field experiment are: (1) Certain fuel hydrocarbons were removed preferentially over others, but the order of preference is dependent upon the geochemical conditions; and (2) In the zones that were augmented with sulfate and/or nitrate, the added electron acceptors were consumed quickly, indicating that enhancement via electron acceptor injection accelerates the biodegradation process. More specifically, in the sulfate-reducing zone, sulfate was utilized with an apparent first-order rate coefficient of approximately 0.1 day(-1). In the combined denitrifying/sulfate-reducing zone, nitrate was utilized preferentially over sulfate, with an apparent first-order rate coefficient of 0.1-0.6 day(-1). However, the data suggest that slow sulfate utilization does occur in the presence of nitrate, i.e., the two processes are not strictly sequential. With regard to the aromatic BTEX hydrocarbons, toluene was preferentially removed under intrinsic conditions; biodegradation of benzene was slow if it occurred at all; augmentation with sulfate preferentially stimulated biodegradation of o-xylene; and ethylbenzene appeared recalcitrant under sulfate-reducing conditions but readily degradable under denitrifying conditions.

  View details for Web of Science ID 000168530600007

  View details for PubMedID 11440242

• Pd-catalyzed hydrodehalogenation of chlorinated compounds: Spectroscopic analysis 2nd International Conference on Remediation of Chlorinated and Recalcitrant Compounds Munakata, N., Lowry, G., Sriwatanapongse, W., Reinhard, M. BATTELLE PRESS. 2000: 229–235

  View details for Web of Science ID 000167101900030

• Enhanced anaerobic in situ bioremediation of fuel hydrocarbons in groundwater at Seal Beach, California International Conference on Groundwater Research Cunningham, J. A., Hopkins, G. D., Reinhard, M., Lebron, C. A. A A BALKEMA PUBLISHERS. 2000: 411–412

  View details for Web of Science ID 000088384300182

• In-situ destruction of chlorinated hydrocarbons in groundwater using catalytic reductive dehalogenation in a reactive well: Testing and operational experiences ENVIRONMENTAL SCIENCE & TECHNOLOGY McNab, W. W., Ruiz, R., Reinhard, M. 2000; 34 (1): 149-153

  View details for Web of Science ID 000084531400042

• Biodegradation residual of 4-octylphenoxyacetic acid in laboratory columns under groundwater recharge conditions ENVIRONMENTAL SCIENCE & TECHNOLOGY Wild, D., Reinhard, M. 1999; 33 (24): 4422-4426

  View details for Web of Science ID 000084252300011

• Occurrence and behavior of wastewater indicators in the Santa Ana River and the underlying aquifers CHEMOSPHERE Ding, W. H., Wu, J., Semadeni, M., Reinhard, M. 1999; 39 (11): 1781-1794

  Abstract

  The occurrence and behavior of wastewater indicator compounds in the Santa Ana River (SAR) water and the underlying aquifer recharged by the SAR has been studied. The SAR contains a high proportion of tertiary treated wastewater effluents, up to 100% during summer and fall. The following water quality parameters were quantified: four specific wastewater indicator compounds, ethylene diaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), a naphthalene dicarboxylate (NDC) isomer, alkylphenol polyethoxy carboxylates (APECs), and selected haloacetic acids (HAAs), nitrate, dissolved oxygen (DO), DOC, total carbohydrate, and phenolic substances. Statistical analysis indicated that normal distribution was adequate to describe the probability distribution of the constituents in most cases. In the river, the concentrations of wastewater indicator compounds decreased as the fraction of storm runoff increased. EDTA and NDC were detected in a monitoring well near the river and in two production wells 1.8 and 2.7 km down gradient with little apparent attenuation. By contrast, NTA, APECs, bromochloro- and dibromoacetic acids appeared to be attenuated significantly during infiltration of river water and groundwater transport.

  View details for Web of Science ID 000082746300002

  View details for PubMedID 10533715

• Initial reactions in anaerobic oxidation of m-xylene by the denitrifying bacterium Azoarcus sp strain T JOURNAL OF BACTERIOLOGY Krieger, C. J., Beller, H. R., Reinhard, M., Spormann, A. M. 1999; 181 (20): 6403-6410

  Abstract

  The initial enzymatic steps in anaerobic m-xylene oxidation were studied in Azoarcus sp. strain T, a denitrifying bacterium capable of mineralizing m-xylene via 3-methylbenzoate. Permeabilized cells of m-xylene-grown Azoarcus sp. strain T catalyzed the addition of m-xylene to fumarate to form (3-methylbenzyl)succinate. In the presence of succinyl coenzyme A (CoA) and nitrate, (3-methylbenzyl)succinate was oxidized to E-(3-methylphenyl)itaconate (or a closely related isomer) and 3-methylbenzoate. Kinetic studies conducted with permeabilized cells and whole-cell suspensions of m-xylene-grown Azoarcus sp. strain T demonstrated that the specific rate of in vitro (3-methylbenzyl)succinate formation accounts for at least 15% of the specific rate of in vivo m-xylene consumption. Based on these findings, we propose that Azoarcus sp. strain T anaerobically oxidizes m-xylene to 3-methylbenzoate (or its CoA thioester) via (3-methylbenzyl)succinate and E-(3-methylphenyl)itaconate (or its CoA thioester) in a series of reactions that are analogous to those recently proposed for anaerobic toluene oxidation to benzoyl-CoA. A deuterium kinetic isotope effect was observed in the (3-methylbenzyl)succinate synthase reaction (and the benzylsuccinate synthase reaction), suggesting that a rate-determining step in this novel fumarate addition reaction involves breaking a C-H bond.

  View details for Web of Science ID 000083006500024

  View details for PubMedID 10515931

  View details for PubMedCentralID PMC103776

• Hydrodehalogenation of 1-to 3-carbon halogenated organic compounds in water using a palladium catalyst and hydrogen gas ENVIRONMENTAL SCIENCE & TECHNOLOGY Lowry, G. V., Reinhard, M. 1999; 33 (11): 1905-1910

  View details for Web of Science ID 000080655400042

• Counter diffusion of isotopically labeled trichloroethylene in silica gel and geosorbent micropores: Column results ENVIRONMENTAL SCIENCE & TECHNOLOGY Werth, C. J., Reinhard, M. 1999; 33 (5): 730-736

  View details for Web of Science ID 000078929000026

• Hydrodehalogenation of halogenated groundwater contaminants with Pd catalysts and H-2 gas 1998 National Conference on Environmental Remediation Science and Technology Lowry, G. V., Reinhard, M. BATTELLE PRESS. 1999: 109–118

  View details for Web of Science ID 000082439400012

• Hydrodechlorination and hydrogenation of aromatic compounds over palladium on alumina in hydrogen-saturated water APPLIED CATALYSIS B-ENVIRONMENTAL Schuth, C., Reinhard, M. 1998; 18 (3-4): 215-221

  View details for Web of Science ID 000076960900004

• Reductive transformation of trichloroethene by cobalamin: Reactivities of the intermediates acetylene, chloroacetylene, and the DCE isomers ENVIRONMENTAL SCIENCE & TECHNOLOGY Semadeni, M., Chiu, P. C., Reinhard, M. 1998; 32 (9): 1207-1213

  View details for Web of Science ID 000073404400025

• Matrix effects on catalyst deactivation in a Pd/H-2 hydrodehalogenation system 1st International Conference on Remediation of Chlorinated and Recalcitrant Compounds Munakata, N., Roberts, P. V., Reinhard, M., McNab, W. BATTELLE PRESS. 1998: 305–310

  View details for Web of Science ID 000075849200047

• Dehalogenation of chlorinated solvents using a palladium catalyst and hydrogen gas 1st International Conference on Remediation of Chlorinated and Recalcitrant Compounds Lowry, G., Reinhard, M., McNab, W. BATTELLE PRESS. 1998: 311–316

  View details for Web of Science ID 000075849200048

• Sequestration of hydrophobic organic contaminants by geosorbents ENVIRONMENTAL SCIENCE & TECHNOLOGY Luthy, R. G., Aiken, G. R., Brusseau, M. L., Cunningham, S. D., Gschwend, P. M., Pignatello, J. J., Reinhard, M., Traina, S. J., Weber, W. J., Westall, J. C. 1997; 31 (12): 3341-3347

  View details for Web of Science ID A1997YJ88200024

• Effects of grain-scale mass transfer on the transport of volatile organics through sediments .2. Column results WATER RESOURCES RESEARCH Werth, C. J., Cunningham, J. A., Roberts, P. V., Reinhard, M. 1997; 33 (12): 2727-2740

  View details for Web of Science ID A1997YJ96400010

• Effects of grain-scale mass transfer on the transport of volatile organics through sediments .1. Model development WATER RESOURCES RESEARCH Cunningham, J. A., Werth, C. J., Reinhard, M., Roberts, P. V. 1997; 33 (12): 2713-2726

  View details for Web of Science ID A1997YJ96400009

• Identification of metabolites from the biological transformation of the nonionic surfactant residue octylphenoxyacetic acid and its brominated analog ENVIRONMENTAL SCIENCE & TECHNOLOGY Fujita, Y., Reinhard, M. 1997; 31 (5): 1518-1524

  View details for Web of Science ID A1997WW94800054

• Effects of temperature on trichloroethylene desorption from silica gel and natural sediments .2. Kinetics ENVIRONMENTAL SCIENCE & TECHNOLOGY Werth, C. J., Reinhard, M. 1997; 31 (3): 697-703

  View details for Web of Science ID A1997WK81500039

• Effects of temperature on trichloroethylene desorption from silica gel and natural sediments .1. Isotherms ENVIRONMENTAL SCIENCE & TECHNOLOGY Werth, C. J., Reinhard, M. 1997; 31 (3): 689-696

  View details for Web of Science ID A1997WK81500038

• BTEX biotransformation under different anaerobic conditions: Field and laboratory evaluations 4th International In Situ and On-Site Bioremediation Symposium Reinhard, M., Beller, H. R., Ball, H. A., Hopkins, G. D., Lebron, C. A. BATTELLE PRESS. 1997: 9–10

  View details for Web of Science ID A1997BH89W00003

• In situ BTEX biotransformation under enhanced nitrate- and sulfate-reducing conditions ENVIRONMENTAL SCIENCE & TECHNOLOGY Reinhard, M., Shang, S., Kitanidis, P. K., Orwin, E., Hopkins, G. D., Lebron, C. A. 1997; 31 (1): 28-36

  View details for Web of Science ID A1997WC40000023

• In situ anaerobic bioremediation of fuel contaminated ground water at Seal Beach, CA 7th International Offshore and Polar Engineering Conference (ISOPE-97) Reinhard, M., Hopkins, G. D., Orwin, E., Lebron, C. A. INTERNATIONAL SOCIETY OFFSHORE& POLAR ENGINEERS. 1997: 539–543

  View details for Web of Science ID A1997BJ14B00081

• Initial reactions in anaerobic ethylbenzene oxidation by a denitrifying bacterium, strain EB1 JOURNAL OF BACTERIOLOGY Ball, H. A., Johnson, H. A., Reinhard, M., Spormann, A. M. 1996; 178 (19): 5755-5761

  Abstract

  Initial reactions in anaerobic oxidation of ethylbenzene were investigated in a denitrifying bacterium, strain EB1. Cells of strain EB1 mineralized ethylbenzene to CO2 under denitrifying conditions, as demonstrated by conversion of 69% of [14C]ethylbenzene to 14CO2. In anaerobic suspensions of strain EB1 cells metabolizing ethylbenzene, the transient formation and consumption of 1-phenylethanol, acetophenone, and an as yet unidentified compound were observed. On the basis of growth experiments and spectroscopic data, the unknown compound is proposed to be benzoyl acetate. Cell suspension experiments using H2(18)O demonstrated that the hydroxyl group of the first product of anoxic ethylbenzene oxidation, 1-phenylethanol, is derived from water. A tentative pathway for anaerobic ethylbenzene mineralization by strain EB1 is proposed.

  View details for Web of Science ID A1996VK78900027

  View details for PubMedID 8824622

  View details for PubMedCentralID PMC178416

• Treatment of 1,2-dibromo-3-chloropropane and nitrate-contaminated water with zero-valent iron or hydrogen/palladium catalysts WATER RESEARCH Siantar, D. P., Schreier, C. G., Chou, C. S., Reinhard, M. 1996; 30 (10): 2315-2322

  View details for Web of Science ID A1996VT98000012

• Identification of wastewater dissolved organic carbon characteristics in reclaimed wastewater and recharged groundwater WATER ENVIRONMENT RESEARCH Fujita, Y., Ding, W. H., Reinhard, M. 1996; 68 (5): 867-876

  View details for Web of Science ID A1996UY29700005

• Transformation of carbon tetrachloride by reduced vitamin B-12 in aqueous cysteine solution ENVIRONMENTAL SCIENCE & TECHNOLOGY Chiu, P. C., Reinhard, M. 1996; 30 (6): 1882-1889

  View details for Web of Science ID A1996UM99100033

• Isolation and characterization of a novel toluene-degrading, sulfate-reducing bacterium APPLIED AND ENVIRONMENTAL MICROBIOLOGY Beller, H. R., Spormann, A. M., Sharma, P. K., Cole, J. R., Reinhard, M. 1996; 62 (4): 1188-1196

  Abstract

  A novel sulfate-reducing bacterium isolated from fuel-contaminated subsurface soil, strain PRTOL1, mineralizes toluene as the sole electron donor and carbon source under strictly anaerobic conditions. The mineralization of 80% of toluene carbon to CO2 was demonstrated in experiments with [ring-U-14C]toluene; 15% of toluene carbon was converted to biomass and nonvolatile metabolic by-products, primarily the former. The observed stoichiometric ratio of moles of sulfate consumed per mole of toluene consumed was consistent with the theoretical ratio for mineralization of toluene coupled with the reduction of sulfate to hydrogen sulfide. Strain PRTOL1 also transforms o- and p-xylene to metabolic products when grown with toluene. However, xylene transformation by PRTOL1 is slow relative to toluene degradation and cannot be sustained over time. Stable isotope-labeled substrates were used in conjunction with gas chromatography-mass spectrometry to investigate the by-products of toluene and xylene metabolism. The predominant by-products from toluene, o-xylene, and p-xylene were benzylsuccinic acid, (2-methylbenzyl)succinic acid, and 4-methylbenzoic acid (or p-toluic acid), respectively. Metabolic by-products accounted for nearly all of the o-xylene consumed. Enzyme assays indicated that acetyl coenzyme A oxidation proceeded via the carbon monoxide dehydrogenase pathway. Compared with the only other reported toluene-degrading, sulfate-reducing bacterium, strain PRTOL1 is distinct in that it has a novel 16S rRNA gene sequence and was derived from a freshwater rather than marine environment.

  View details for Web of Science ID A1996UD95000010

  View details for PubMedID 8919780

• Monoaromatic hydrocarbon transformation under anaerobic conditions at Seal Beach, California: Laboratory studies ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Ball, H. A., Reinhard, M. 1996; 15 (2): 114-122

  View details for Web of Science ID A1996TU20700007

• Identification of organic residues in tertiary effluents by GC/EI-MS, GC/CI-MS and GC/TSQ-MS FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY Ding, W. H., Fujita, Y., Aeschimann, R., Reinhard, M. 1996; 354 (1): 48-55

  View details for Web of Science ID A1996TN47100009

• BY-PRODUCTS OF ANAEROBIC ALKYLBENZENE METABOLISM USEFUL AS INDICATORS OF IN-SITU BIOREMEDIATION ENVIRONMENTAL SCIENCE & TECHNOLOGY Beller, H. R., Ding, W. H., Reinhard, M. 1995; 29 (11): 2864-2870

  View details for Web of Science ID A1995TC85600042

  View details for PubMedID 22206536

• CATALYTIC HYDRODEHALOGENATION OF CHLORINATED ETHYLENES USING PALLADIUM AND HYDROGEN FOR THE TREATMENT OF CONTAMINATED WATER CHEMOSPHERE Schreier, C. G., Reinhard, M. 1995; 31 (6): 3475-3487

  View details for Web of Science ID A1995RX18200012

• THE ROLE OF IRON IN ENHANCING ANAEROBIC TOLUENE DEGRADATION IN SULFATE-REDUCING ENRICHMENT CULTURES MICROBIAL ECOLOGY Beller, H. R., Reinhard, M. 1995; 30 (1): 105-114

  View details for Web of Science ID A1995RF81800009

• METALLOCOENZYME-MEDIATED REDUCTIVE TRANSFORMATION OF CARBON-TETRACHLORIDE IN TITANIUM(III) CITRATE AQUEOUS-SOLUTION ENVIRONMENTAL SCIENCE & TECHNOLOGY Chiu, P. C., Reinhard, M. 1995; 29 (3): 595-603

  View details for Web of Science ID A1995QJ90800021

  View details for PubMedID 22200267

• In situ demonstration of anaerobic BTEX biodegradation through controlled-release experiments 3rd International In Situ and On-Site Bioreclamation Symposium Reinhard, M., Hopkins, G. D., Orwin, E., Shang, S. B., Lebron, C. A. BATTELLE PRESS. 1995: 263–70

  View details for Web of Science ID A1995BG31T00028

• REDUCTIVE DEHALOGENATION OF HEXACHLORETHANE, CARBON-TETRACHLORIDE, AND BROMOFORM BY ANTHRAHYDROQUINONE DISULFONATE AND HUMIC-ACID ENVIRONMENTAL SCIENCE & TECHNOLOGY Curtis, G. P., Reinhard, M. 1994; 28 (13): 2393-2401

  View details for Web of Science ID A1994PV17100029

  View details for PubMedID 22176060

• CHEMICAL-IONIZATION MASS-SPECTRA OF LINEAR ALCOHOL POLYETHOXY CARBOXYLATES AND POLYETHYLENE-GLYCOL DICARBOXYLATES RAPID COMMUNICATIONS IN MASS SPECTROMETRY Ding, W. H., Fujita, Y., Reinhard, M. 1994; 8 (12): 1016-1020

  View details for Web of Science ID A1994QF62200020

• TRANSFORMATION OF CHLORINATED ORGANIC-COMPOUNDS BY IRON AND MANGANESE POWDERS IN BUFFERED WATER AND IN LANDFILL LEACHATE CHEMOSPHERE Schreier, C. G., Reinhard, M. 1994; 29 (8): 1743-1753

  View details for Web of Science ID A1994PU90800014

• TRANSFORMATION OF CARBON-TETRACHLORIDE BY PYRITE IN AQUEOUS-SOLUTION ENVIRONMENTAL SCIENCE & TECHNOLOGY KRIEGMANKING, M. R., Reinhard, M. 1994; 28 (4): 692-700

  View details for Web of Science ID A1994ND55000029

  View details for PubMedID 22196555

• DESORPTION OF HALOGENATED ORGANICS FROM MODEL SOLIDS, SEDIMENTS, AND SOIL UNDER UNSATURATED CONDITIONS .1. ISOTHERMS ENVIRONMENTAL SCIENCE & TECHNOLOGY Farrell, J., Reinhard, M. 1994; 28 (1): 53-62

  View details for Web of Science ID A1994MP60400018

  View details for PubMedID 22175833

• DESORPTION OF HALOGENATED ORGANICS FROM MODEL SOLIDS, SEDIMENTS, AND SOIL UNDER UNSATURATED CONDITIONS .2. KINETICS ENVIRONMENTAL SCIENCE & TECHNOLOGY Farrell, J., Reinhard, M. 1994; 28 (1): 63-72

  View details for Web of Science ID A1994MP60400019

  View details for PubMedID 22175834

• DESORPTION OF TRICHLOROETHYLENE IN AQUIFER MATERIAL - RATE LIMITATION AT THE GRAIN SCALE ENVIRONMENTAL SCIENCE & TECHNOLOGY Grathwohl, P., Reinhard, M. 1993; 27 (12): 2360-2366

  View details for Web of Science ID A1993ME57800022

• SIMILARITY-BASED SEARCH AND EVALUATION OF ENVIRONMENTALLY RELEVANT PROPERTIES FOR ORGANIC-COMPOUNDS IN COMBINATION WITH THE GROUP-CONTRIBUTION APPROACH JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES Drefahl, A., Reinhard, M. 1993; 33 (6): 886-895

  View details for Web of Science ID A1993MJ98800011

• TRANSFORMATION OF CARBON-TETRACHLORIDE IN THE PRESENCE OF SULFIDE, BIOTITE, AND VERMICULITE ENVIRONMENTAL SCIENCE & TECHNOLOGY KRIEGMANKING, M. R., Reinhard, M. 1992; 26 (11): 2198-2206

  View details for Web of Science ID A1992JV98900025

• ANAEROBIC DEGRADATION OF TOLUENE AND XYLENE BY AQUIFER MICROORGANISMS UNDER SULFATE-REDUCING CONDITIONS APPLIED AND ENVIRONMENTAL MICROBIOLOGY Edwards, E. A., WILLS, L. E., Reinhard, M., GRBICGALIC, D. 1992; 58 (3): 794-800

  Abstract

  Toluene and the three isomers of xylene were completely mineralized to CO2 and biomass by aquifer-derived microorganisms under strictly anaerobic conditions. The source of the inoculum was gasoline-contaminated sediment from Seal Beach, Calif. Evidence confirming that sulfate was the terminal electron acceptor is presented. Benzene and ethylbenzene were not degraded under the experimental conditions used. Successive transfers of the mixed cultures that were enriched from aquifer sediments retained the ability to degrade toluene and xylenes. Greater than 90% of 14C-labeled toluene or 14C-labeled o-xylene was mineralized to 14CO2. The doubling time for the culture grown on toluene or m-xylene was about 20 days, and the cell yield was about 0.1 to 0.14 g of cells (dry weight) per g of substrate. The accumulation of sulfide in the cultures as a result of sulfate reduction appeared to inhibit degradation of aromatic hydrocarbons.

  View details for Web of Science ID A1992HH28400003

  View details for PubMedID 1575482

• MICROBIAL-DEGRADATION OF TOLUENE UNDER SULFATE-REDUCING CONDITIONS AND THE INFLUENCE OF IRON ON THE PROCESS APPLIED AND ENVIRONMENTAL MICROBIOLOGY Beller, H. R., GRBICGALIC, D., Reinhard, M. 1992; 58 (3): 786-793

  Abstract

  Toluene degradation occurred concomitantly with sulfate reduction in anaerobic microcosms inoculated with contaminated subsurface soil from an aviation fuel storage facility near the Patuxent River (Md.). Similar results were obtained for enrichment cultures in which toluene was the sole carbon source. Several lines of evidence suggest that toluene degradation was directly coupled to sulfate reduction in Patuxent River microcosms and enrichment cultures: (i) the two processes were synchronous and highly correlated, (ii) the observed stoichiometric ratios of moles of sulfate consumed per mole of toluene consumed were consistent with the theoretical ratio for the oxidation of toluene to CO2 coupled with the reduction of sulfate to hydrogen sulfide, and (iii) toluene degradation ceased when sulfate was depleted, and conversely, sulfate reduction ceased when toluene was depleted. Mineralization of toluene was confirmed in experiments with [ring-U-14C]toluene. The addition of millimolar concentrations of amorphous Fe(OH)3 to Patuxent River microcosms and enrichment cultures either greatly facilitated the onset of toluene degradation or accelerated the rate once degradation had begun. In iron-amended microcosms and enrichment cultures, ferric iron reduction proceeded concurrently with toluene degradation and sulfate reduction. Stoichiometric data and other observations indicate that ferric iron reduction was not directly coupled to toluene oxidation but was a secondary, presumably abiotic, reaction between ferric iron and biogenic hydrogen sulfide.

  View details for Web of Science ID A1992HH28400002

  View details for PubMedID 1575481

• DEVELOPMENT OF A PRODUCT SCREENING PROTOCOL TO MINIMIZE MARINE ENVIRONMENTAL IMPACTS OF OIL PRODUCTION CHEMICALS USED OFFSHORE WATER SCIENCE AND TECHNOLOGY Vik, E. A., Berg, J. D., Bakke, S., OFJORD, G. D., Reinhard, M. 1992; 25 (3): 85-92

  View details for Web of Science ID A1992HX91700010

• TRANSFORMATION AND SORPTION OF 1,2-DIBROMO-3-CHLOROPROPANE IN SUBSURFACE SAMPLES COLLECTED AT FRESNO, CALIFORNIA JOURNAL OF ENVIRONMENTAL QUALITY DEELEY, G. M., Reinhard, M., STEARNS, S. M. 1991; 20 (3): 547-556

  View details for Web of Science ID A1991FZ67800008

• A FIELD EXPERIMENT FOR THE ANAEROBIC BIOTRANSFORMATION OF AROMATIC HYDROCARBON COMPOUNDS AT SEAL BEACH, CALIFORNIA INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION Reinhard, M., WILLS, L. E., Ball, H. A., Harmon, T., PHIPPS, D. W., RIDGWAY, H. F., EISMAN, M. P. BUTTERWORTH-HEINEMANN. 1991: 487–496

  View details for Web of Science ID A1991BU85H00034

• BIOTRANSFORMATION OF MONOAROMATIC HYDROCARBONS UNDER ANOXIC CONDITIONS INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION Ball, H. A., Reinhard, M., McCarty, P. L. BUTTERWORTH-HEINEMANN. 1991: 458–463

  View details for Web of Science ID A1991BU85H00030

• DEGRADATION OF TOLUENE AND PARA-XYLENE IN ANAEROBIC MICROCOSMS - EVIDENCE FOR SULFATE AS A TERMINAL ELECTRON-ACCEPTOR ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Haag, F., Reinhard, M., McCarty, P. L. 1991; 10 (11): 1379-1389

  View details for Web of Science ID A1991GM68800002

• ANAEROBIC DEGRADATION OF TOLUENE AND XYLENE - EVIDENCE FOR SULFATE AS THE TERMINAL ELECTRON-ACCEPTOR INTERNATIONAL SYMP ON IN SITU AND ON-SITE BIORECLAMATION Edwards, E. A., WILLS, L. E., GRBICGALIC, D., Reinhard, M. BUTTERWORTH-HEINEMANN. 1991: 463–471

  View details for Web of Science ID A1991BU85H00031

• ABIOTIC DEHALOGENATION OF 1,2-DICHLOROETHANE AND 1,2-DIBROMOETHANE IN AQUEOUS-SOLUTION CONTAINING HYDROGEN-SULFIDE ENVIRONMENTAL SCIENCE & TECHNOLOGY Barbash, J. E., Reinhard, M. 1989; 23 (11): 1349-1358

  View details for Web of Science ID A1989AX23600008

• BIOTRANSFORMATION OF HALOGENATED AND NONHALOGENATED OCTYLPHENOL POLYETHOXYLATE RESIDUES UNDER AEROBIC AND ANAEROBIC CONDITIONS ENVIRONMENTAL SCIENCE & TECHNOLOGY Ball, H. A., Reinhard, M., McCarty, P. L. 1989; 23 (8): 951-961

  View details for Web of Science ID A1989AH87000011

• REACTIVITY OF SULFUR NUCLEOPHILES TOWARD HALOGENATED ORGANIC-COMPOUNDS IN NATURAL-WATERS ACS SYMPOSIUM SERIES Barbash, J. E., Reinhard, M. 1989; 393: 101-138

  View details for Web of Science ID A1989AC50900008

• REACTIVITIES OF HYPOCHLOROUS AND HYPOBROMOUS ACID, CHLORINE MONOXIDE, HYPOBROMOUS ACIDIUM ION, CHLORINE, BROMINE, AND BROMINE CHLORIDE IN ELECTROPHILIC AROMATIC-SUBSTITUTION REACTIONS WITH P-XYLENE IN WATER ENVIRONMENTAL SCIENCE & TECHNOLOGY Voudrias, E. A., Reinhard, M. 1988; 22 (9): 1049-1056

  View details for Web of Science ID A1988P962200014

  View details for PubMedID 22148659

• A KINETIC-MODEL FOR THE HALOGENATION OF P-XYLENE IN AQUEOUS HOCL SOLUTIONS CONTAINING CL- AND BR- ENVIRONMENTAL SCIENCE & TECHNOLOGY Voudrias, E. A., Reinhard, M. 1988; 22 (9): 1056-1062

  View details for Web of Science ID A1988P962200015

  View details for PubMedID 22148660

• IDENTIFICATION AND QUANTIFICATION OF HALOGENATED AND NON-HALOGENATED OCTYLPHENOL POLYETHOXYLATE RESIDUES BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY USING ELECTRON IONIZATION AND CHEMICAL IONIZATION BIOMEDICAL AND ENVIRONMENTAL MASS SPECTROMETRY Stephanou, E., Reinhard, M., Ball, H. A. 1988; 15 (5): 275-282

  View details for Web of Science ID A1988M331500006

• ATHIAS - AN INFORMATION-SYSTEM FOR ABIOTIC TRANSFORMATIONS OF HALOGENATED HYDROCARBONS IN AQUEOUS-SOLUTION CHEMOSPHERE ELLENRIEDER, W., Reinhard, M. 1988; 17 (2): 331-344

  View details for Web of Science ID A1988M315300012

• SPECIFIC ANALYSIS OF TRACE ORGANICS IN WATER USING GAS-CHROMATOGRAPHY AND MASS-SPECTROSCOPY JOURNAL OF ENVIRONMENTAL PATHOLOGY TOXICOLOGY AND ONCOLOGY Reinhard, M., SCHREINER, J. E., Everhart, T., Graydon, J. 1987; 7 (7-8): 417-435

  Abstract

  For the characterization of a broad range of compounds in water, various methods have been combined into a procedure. The reliability and limitations of this approach have been discussed in this paper. This combined procedure represents only a preliminary solution to the problem of organic materials in water. Future improvements will be possible as new columns, instruments, and software become available. Physico-chemical constants of trace organic compounds have been used to predict and interpret their extraction and pre-separation in an analytical scheme where purge/trap and solvent extraction methods are combined to measure a broad range of organic materials. This approach is limited by the scarcity of thermodynamic data; such data must be generated if predictive models of pollutant behavior in analytical as well as environmental systems are to be developed. In summary, the basic requirements for analyzing trace organic compounds in tertiary effluents and drinking waters include: The analysis must be based on a small sample size (up to 1 liter). Samples of one gallon or more are costly to ship and difficult to process and store. Samples of one liter or less can be shipped at moderate cost and stored in medium-sized refrigerators. The detection limit for most trace contaminants must be in the lower nanogram per liter range. At detection limits of 1 microgram/l and above, the removal (or formation) of many contaminants cannot be determined precisely. For conclusive results, variabilities of the procedure, the compound, and concentration at a sampling point have to be considered and investigated. Generally, approximately 30 samples are needed to establish a concentration distribution (1).

  View details for Web of Science ID A1987L461800029

  View details for PubMedID 3694488

• OPERATIONAL EXPERIENCES WITH ACTIVATED CARBON ADSORBERS AT WATER FACTORY 21 JOURNAL OF ENVIRONMENTAL PATHOLOGY TOXICOLOGY AND ONCOLOGY McCarty, P. L., Argo, D., Reinhard, M. 1987; 7 (7-8): 319-338

  View details for Web of Science ID A1987L461800022

  View details for PubMedID 3694480

• A NATURAL GRADIENT EXPERIMENT ON SOLUTE TRANSPORT IN A SAND AQUIFER .4. SORPTION OF ORGANIC SOLUTES AND ITS INFLUENCE ON MOBILITY WATER RESOURCES RESEARCH Curtis, G. P., Roberts, P. V., Reinhard, M. 1986; 22 (13): 2059-2067

  View details for Web of Science ID A1986F309300028

• REACTION-PRODUCTS AND RATES OF DISAPPEARANCE OF SIMPLE BROMOALKANES, 1,2-DIBROMOPROPANE, AND 1,2-DIBROMOETHANE IN WATER ENVIRONMENTAL SCIENCE & TECHNOLOGY Vogel, T. M., Reinhard, M. 1986; 20 (10): 992-997

  View details for Web of Science ID A1986E251900005

  View details for PubMedID 22257396

• REMOVING TRACE ORGANICS BY REVERSE-OSMOSIS USING CELLULOSE-ACETATE AND POLYAMIDE MEMBRANES JOURNAL AMERICAN WATER WORKS ASSOCIATION Reinhard, M., Goodman, N. L., McCarty, P. L., ARGO, D. G. 1986; 78 (4): 163-174

  View details for Web of Science ID A1986A742900004

• SORPTION OF HYDROPHOBIC ORGANIC-COMPOUNDS BY SEDIMENTS ACS SYMPOSIUM SERIES Curtis, G. P., Reinhard, M., Roberts, P. V. 1986; 323: 191-216

  View details for Web of Science ID A1986F047300010

• ABIOTIC ORGANIC-REACTIONS AT MINERAL SURFACES ACS SYMPOSIUM SERIES Voudrias, E. A., Reinhard, M. 1986; 323: 462-486

  View details for Web of Science ID A1986F047300022

• MOLECULAR-WEIGHT DISTRIBUTION OF DISSOLVED ORGANIC-CARBON AND DISSOLVED ORGANIC HALOGEN IN ADVANCED TREATED WASTEWATERS ENVIRONMENTAL SCIENCE & TECHNOLOGY Reinhard, M. 1984; 18 (6): 410-415

  View details for Web of Science ID A1984ST45000008

  View details for PubMedID 22247941

• OCCURRENCE AND DISTRIBUTION OF ORGANIC-CHEMICALS IN 2 LANDFILL LEACHATE PLUMES ENVIRONMENTAL SCIENCE & TECHNOLOGY Reinhard, M., Goodman, N. L., Barker, J. F. 1984; 18 (12): 953-961

  View details for Web of Science ID A1984TV09000015

• MOVEMENT OF ORGANIC CONTAMINANTS IN GROUNDWATER - IMPLICATIONS FOR WATER-SUPPLY JOURNAL AMERICAN WATER WORKS ASSOCIATION Roberts, P. V., Reinhard, M., Valocchi, A. J. 1982; 74 (8): 408-413

  View details for Web of Science ID A1982PA37600011

• OCCURRENCE OF BROMINATED ALKYLPHENOL POLYETHOXY CARBOXYLATES IN MUTAGENIC WASTEWATER CONCENTRATES ENVIRONMENTAL SCIENCE & TECHNOLOGY Reinhard, M., Goodman, N., Mortelmans, K. E. 1982; 16 (6): 351-362

  View details for Web of Science ID A1982NR28100019

• TRACE ORGANICS IN GROUNDWATER ENVIRONMENTAL SCIENCE & TECHNOLOGY McCarty, P. L., Reinhard, M., Rittmann, B. E. 1981; 15 (1): 40-?

  View details for Web of Science ID A1981KW80400007

• METHANOGENIC DECOMPOSITION OF FERULIC ACID, A MODEL LIGNIN DERIVATIVE APPLIED AND ENVIRONMENTAL MICROBIOLOGY Healy, J. B., Young, L. Y., Reinhard, M. 1980; 39 (2): 436-444

  Abstract

  Ferulic acid, a model lignin derivative, was observed to be biodegradable to methane and carbon dioxide under strict anaerobic conditions. This conversion appears to be carried out by a consortium of bacteria similar to that previously described for the methanogenic degradation of benzoic acid. A temporary buildup of acetate in these cultures indicates that it is a likely intermediate and precursor for methane formation. An analog of coenzyme M, 2-bromoethanesulfonic acid (BESA), inhibited gas production and enhanced the buildup of propionate, butyrate, isobutyrate, and isovalerate. Phenylacetate, cinnamate, 3-phenylpropionate, benzoate, cyclohexane carboxylate, adipate, and pimelate were also detected in BESA-inhibited cultures. A pathway is proposed which includes these various acids as possible intermediates in the methanogenic degradation of ferulic acid. This model overlaps previously described benzoic acid degradation pathways, suggesting that this type of anaerobic degradation may be common for aromatic compounds.

  View details for Web of Science ID A1980JJ09500027

  View details for PubMedID 16345517

• CHARACTERIZATION OF ORGANIC MATERIALS IN ADVANCED TREATED WASTE-WATER Reinhard, M., Everhart, E. T., Graydon, J. W., McCarty, P. L. AMER CHEMICAL SOC. 1980: 83-ENVR

  View details for Web of Science ID A1980JJ81300739

• TRACE ORGANICS REMOVAL BY ADVANCED WASTEWATER-TREATMENT JOURNAL WATER POLLUTION CONTROL FEDERATION McCarty, P. L., Reinhard, M. 1980; 52 (7): 1907-1922

  View details for Web of Science ID A1980KB91800006

• ORGANIC CONTAMINANT BEHAVIOR DURING GROUNDWATER RECHARGE JOURNAL WATER POLLUTION CONTROL FEDERATION Roberts, P. V., McCarty, P. L., Reinhard, M., Schreiner, J. 1980; 52 (1): 161-172

  View details for Web of Science ID A1980JD17700019

• TRACE ORGANICS REMOVAL BY ADVANCED WASTE TREATMENT JOURNAL OF THE ENVIRONMENTAL ENGINEERING DIVISION-ASCE Reinhard, M., Dolce, C. J., McCarty, P. L., ARGO, D. G. 1979; 105 (4): 675-693

  View details for Web of Science ID A1979HL80500005

• OPERATIONAL EXPERIENCES WITH ACTIVATED CARBON ADSORBERS AT WATER FACTORY 21 JOURNAL AMERICAN WATER WORKS ASSOCIATION McCarty, P. L., Argo, D., Reinhard, M. 1979; 71 (11): 683-689

  View details for Web of Science ID A1979HX97200013