Bioremediation of TCE and Hexavalent Chromium Contamination: Comparing Bench-Scale Treatability Studies to the In Situ Microcosm Array(ABSTRACT)

摘要

We present a novel tool for conducting treatability studies in situ without releasing any chemicals into the environment. The technology, called the In Situ Microcosm Array (ISMA), is a field-deployable device that fits down any standard monitoring well typically measuring 4 inches in inner diameter. The ISMA is designed to perform flow-through, sediment-column microcosms in the subsurface under in situ conditions without releasing any chemicals into the environment. The selfcontained device consists of a stainless steel pipe featuring an array of sediment columns (microcosms) and is equipped with multi-channel peristaltic pumps and electronics enabling groundwater to be drawn directly from the subsurface formation and to be fed as influent to multiple microcosms submerged to the depth of interest. In a standard configuration, the ISMA simultaneously feeds nine continuous-flow microcosms, allowing for the comparison of up to three different approaches to in situ remediation in triplicate, at the same time in the same well. During the course of the deployment, effluent from each column is captured in separate dedicated effluent collection vessels. After in situ incubation, all of the effluent is transported back to the laboratory for chemical analyses, performance assessment, economic analysis and technology ranking.