Dr. Michelle M. Scherer
Donald E. Bently Professor of Engineering, Civil and Environmental Engineering Department
University of Iowa
Dr. Michelle M. Scherer is a Donald E. Bently Professor of Engineering in the Department of Civil and Environmental Engineering at the University of Iowa. Dr. Scherer’s expertise is in environmental geochemistry including redox reactions at mineral-water interfaces and contaminant fate in soils and sediments. She has published over 50 journal articles and her work has been cited over 3000 times. She has been recognized with 2018 Project of the Year Award by SERDP and the Malcolm Pirnie/AEESP Frontier in Research Award in 2010. She served as a member of EPA’s Environmental Engineering Scientific Advisory Board and as an Associate Editor of Environmental Science and Technology. She received her Ph.D. in Environmental Science and Engineering from the Oregon Graduate Institute of Science and Technology, an M.S. in Civil and Environmental Engineering from the University of Connecticut and a B.S. in Systems Engineering from the University of Virginia.
Abiotic Reduction of Chlorinated Solvents by Iron Minerals
Natural attenuation of PCE and TCE through biological degradation has been extensively studied and is widely accepted to contribute to PCE and TCE degradation. It is still unclear, however, whether abiotic degradation of PCE and TCE by iron (Fe) minerals contributes to abiotic natural attenuation (ANA). We present evidence that suggests magnetite and clay minerals are alone unlikely to reduce PCE and TCE fast enough to significantly contribute to the natural attenuation of PCE and TCE in anoxic plumes. Under reducing conditions where high concentrations of ferrous iron may be present, however, active precipitation of metastable, intermediate mineral phases in the presence of magnetite or clay minerals form and may contribute to abiotic natural attenuation of PCE and TCE. The lack of compelling evidence for PCE and TCE reduction by magnetite suggests that magnetite and Fe-containing clay minerals already present in aquifer sediments (i.e., static conditions) may not contribute to ANA. Dynamic conditions and high Fe(II) concentrations that favor active precipitation of minerals, such as Fe(OH)2(s) in the presence of magnetite or clay minerals, however, may lead to PCE and TCE reduction that could help attenuate PCE and TCE.
Co-Authors: Drew Latta, Anke Neumann, Thomas Robinson, and Jim Entwistle