472311 Kinetics of Simultaneous Transformation of Co-Existing Mixed Contaminant Media of Cr(VI) and TCE Using Nanoscale Zero Valent Iron (nZVI)

Wednesday, November 16, 2016: 2:10 PM
Union Square 13 (Hilton San Francisco Union Square)
Daniel Attoh, Aadarsh Shah and Ramesh Chawla, Chemical Engineering, Howard University, Washington, DC

Industrialization has helped advance technology but at the cost of contaminating the natural environment. Several products and by-products of industrial processes are very toxic and hazardous to the health of terrestrial and aquatic life forms. Wastewater and other industrial effluents leach through the earth crust, adsorb on to the surface of soil particles and contaminate subsurface aquifers resulting in the pollution of ground water and many drinking water sources. Among the numerous pollutants co-existing in groundwater and subsurface aquifers, Hexavalent Chromium, Cr(VI), and Trichloroethylene, TCE, have been classified by the USEPA as known carcinogens. Thus, remediation efforts to remove/convert them to non-toxic forms are a priority. A survey of more recent research literature, shows many successful attempts using nanoscale Zero Valent Iron (nZVI), to individually reduce Cr(VI) to its benign form Cr(III) and de-halogenate TCE, but none of these studies have attempted to investigate simultaneous transformation of co-existing Cr(VI)–TCE mixed contaminant media and the associated synergistic or antagonistic effects. Using nZVI to remediate Cr(VI)-TCE mixtures has significant advantages including: very low to zero toxicity to the environment, abundance and presence of ZVI in the subsurface, and the ability to degrade TCE and Cr(VI) to less toxic forms.

Results of kinetic analysis using nZVI as a single transforming agent to degrade a mixed contaminant media of Cr(VI)-TCE in aqueous and soil systems will be presented for various pH and temperature values. Application to subsurface hazardous waste remediation contaminated with multiple contaminants will be discussed.


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See more of this Session: Environmental Advances in Nuclear and Hazardous Waste Treatment
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