Honors & Awards


  • ARCS Fellow, Achievement Rewards for College Scientists (2016-2017)
  • Fellow, Stanford Graduate Fellows in Science and Engineering (SGF) (2014-2016)
  • Graduate Research Fellow, National Science Foundation (2011-2014)

Education & Certifications


  • M.S., Stanford University, Earth System Science (2015)
  • M.S., Stanford University, Environmental Engineering and Science (2013)
  • B.S., University of Texas at Austin, Civil Engineering (2011)

Stanford Advisors


All Publications


  • Imaging geochemical heterogeneities using inverse reactive transport modeling: An example relevant for characterizing arsenic mobilization and distribution ADVANCES IN WATER RESOURCES Fakhreddine, S., Lee, J., Kitanidis, P. K., Fendorf, S., Rolle, M. 2016; 88: 186-197
  • Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge ENVIRONMENTAL SCIENCE & TECHNOLOGY Fakhreddine, S., Dittmar, J., Phipps, D., Dadakis, J., Fendorf, S. 2015; 49 (13): 7802-7809

    Abstract

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration.

    View details for DOI 10.1021/acs.est.5b01140

    View details for Web of Science ID 000357840300038