Parallel In Situ Screening of Remediation Strategies for Improved Decision Making, Remedial Design, and Cost Savings

摘要

This report summarizes the development and demonstration of a new tool for remedial design, the in situ microcosm array (ISMA). It may serve potential end users as a general guide on how to utilize the ISMA technology in the design and interpretation of in situ feasibility studies. Before in situ remediation can be implemented at a hazardous waste site, bench-scale or fieldscale feasibility studies are required. These are typically conducted in static batch-bottle microcosms, while an alternative approach, continuous-flow column studies, are rare in the remediation industry. Although scientifically constituting the gold standard approach to studying transport and reaction phenomena in saturated media, column studies are avoided due to a combination of factors including: considerable costs; complexity and difficulty in performing multiple replicates; and the requirement of considerable operator time. Although batch bottle tests may be adequate for qualitative screening of remedial design options, they are generally considered to have poor quantitative predictive power. In contrast, column studies are expected to produce both reliable qualitative and quantitative data, as they create a more realistic reflection of subsurface realities and the associated difficulty of delivering the remedial agent to where the contaminants of concern reside. On the small-scale, the ISMA technology answers this challenge by creating a platform for standardized flow-through sediment column experiments, and thus makes the more sophisticated continuous-flow evaluation method more accessible to the Department of Defense and to the environmental restoration industry.