@article{FREIM_BICKMORE_VARNELL_FOGEL_A. NEWMAN_2013, title={The Role of Solid Amendments in Promoting the Accelerated Anaerobic Bioremediation of Groundwater Containing High Concentrations of cis- 1,2-Dichloroethene}, url={https://aguassubterraneas.abas.org/asubterraneas/article/view/27845}, abstractNote={<p>In-situ anaerobic bioremediation is an elegant method for decontaminating<br />groundwater containing halogenated hydrocarbons and other toxic contaminants.<br />Successful bioremediation is predicated on establishing and maintaining groundwater that<br />is deoxygenated, electrochemically reducing and pH neutral. Solid remediation<br />amendments, including zero valent metals and carbonate buffers, provide an opportunity<br />to establish and maintain the fertile environment that supports effective anaerobic<br />bioremediation. Zero valent metals are strong reductants that can rapidly render the<br />affected groundwater deoxygenated and electrochemically reducing. Similarly, calcium<br />carbonate is a slow-acting base that has long-term buffering capabilities to help maintain<br />pH neutral conditions. This approach was successfully employed at a large industrial<br />facility in the Southwestern U.S. where prior remediation efforts had resulted in a slowly<br />degrading cis-1,2-dichloroethene plume with concentrations as high as 250 mg/L. This<br />remediation program involved adding sub-micrometer zero valent metal, calcium<br />carbonate and emulsified vegetable oil (EVO) to 60 injection wells within a 120 meters<br />long by 30 meters wide treatment area. The product’s small particle size allowed for a<br />uniform distribution of the solid remediation amendments within the treatment area at<br />injection pressures ranging from 200-600 kPa. Shortly after applying the remediation<br />amendments, an acid-resistant microbial consortium containing dehalococcoides<br />etheneogenes was added to 15 of the injection wells. Within seven months of product<br />application, c-1,2-DCE concentrations had decreased by over 99% in the most<br />contaminated monitoring well with a similar response in down gradient monitoring wells.<br />Vinyl chloride concentrations peaked about six months after product application and have<br />since degraded mostly to ethene, indicating that a biotic pathway was the primary<br />degradation mechanism.</p>}, journal={Águas Subterrâneas}, author={FREIM, JOHN and BICKMORE, CLINT and VARNELL, RICHARD and FOGEL, SAM and A. NEWMAN, WILLIAN}, year={2013}, month={fev.} }