Remediation of Soil and Groundwater with Zerovalent Iron (ZVI): A Chemist’s Perspective on Material Selection and Remedy Design



In the 25 years since the use of zerovalent iron (ZVI) for removing contaminants from environmental media became popular, this field has grown and diversified to become a major aspect of environmental engineering. Researchers continue to develop novel formulations of ZVI with enhanced performance and demonstrate applications to more diverse contaminants; while practitioners routinely acquire ZVI from multiple vendors for use in a variety of mature—in situ and ex situ—remediation technologies. The collective body of fundamental and applied knowledge regarding remediation applications of ZVI has become too vast for anyone to manage, so we have been working to define “core concepts” that provide a framework for relating prior results to future outcomes. The most fundamental example of this is what we’ve recently started calling the “standard kinetic model”, which relates the dose of ZVI to contaminant reduction rates via the reactive surface area of the ZVI. A more challenging problem is the estimation of reduction rates for less common contaminants using data on the more common contaminants. An even more challenging problem is predicting the efficiency (dechlorination of contaminants vs. reduction of water to hydrogen) or selectivity (vinyl chloride vs. acetylene formed) from a priori characteristics of the treatment conditions. This presentation will summarize several core concepts that can be used by practitioners to design new remediation applications of ZVI (e.g., interpret the results of treatability studies), or explain the performance of existing ZVI-based remedies.

The Presenters:

Prof. Paul G. Tratnyek, Ph.D.
Dr. Paul G. Tratnyek currently is a Professor in the School of Public Health at the Oregon Health & Science University in Portland, OR. He received his Ph.D. in Applied Chemistry from the Colorado School of Mines in 1987; served as a National Research Council Postdoctoral Fellow at the U.S. Environmental Protection Agency Laboratory in Athens, GA, in 1988; and as a Research Associate at the Swiss Federal Institute for Water Resources and Water Pollution Control (EAWAG) from 1989 to 1991. In 1991, Tratnyek joined the faculty in the Department of Environmental Science and Engineering at the Oregon Graduate Institute (OGI) where he became involved in OGI’s Center for Groundwater Research and the University Consortium Solvents-In-Groundwater research program based at the University of Waterloo. Through that connection, he became involved in research on zerovalent iron (ZVI) for remediation of contaminated groundwater. Since then, his areas of research have expanded to include most aspects of in situ chemical reduction and oxidation (ISCR, ISCO), including some of the earliest work on abiotic reduction of contaminants and the largest body of high-impact research on ZVI. Most of his recent and on-going research relates to enhanced formulations of ZVI (e.g., by sulfidation), treatment of high-recalcitrant emerging contaminants (e.g., 1,2,3-trichloropropane), and the characterization of in situ redox processes involved in ISCR and abiotic natural attention (ANA). For more details, see

Jeff Roberts
Jeff is the Operations Manager at SiREM with extensive technical experience in the laboratory assessment and field implementation of soil, sediment and groundwater remediation technologies at sites containing contaminants including chlorinated solvents, petroleum hydrocarbons, emerging contaminants and other recalcitrant compounds. Over the past 18 years he has conducted and managed hundreds of bench-scale batch and column treatability studies and has technical experience in the growth, scale up and field implementation of several anaerobic microbial cultures for bioremediation remedies. Jeff has several years of passive sampling experience and was a lead member in the development of the SP3™ sampler.