Remediation Technologies for a Large Pesticide-Contaminated Site: Enclosure, Alkaline Hydrolysis, and Bioventing

摘要

A novel treatment train consisting of enclosure, in situ alkaline hydrolysis, pump-and-treat and bioventing has been proposed to remediate a large, pesticide- contaminated site located on the northwest coast of Denmark. Of the more than 100 con- taminants found at the site, parathion is the major concern. In 2006, an area encompassing 20,000 m~2 was enclosed with 14-meter deep steel sheet piling and a plastic membrane cap. Concurrently, a treatability study involving six remediation technologies was carried out. A pilot-scale demonstration of the selected treatment train was subsequently per- formed. This demonstration included the construction of a 4 x 4 meter, 16-well test field as well as investigations of parathion hydrolysis, buffer capacities, geochemical changes due to high pH-values and the effect of high pH on the microcosm. Infiltration of 30 m~3 of diluted caustic soda into the test field, water treatment of the abstracted groundwater and bioventing tests were not yet complete at the time of press. Results indicate that the treatment train is a suitable selection for full-scale application.