The application of Daramend® reagent served to reductively dechlorinate and subsequently mineralize chlorinated herbicides and pesticides present in soil at a Former W.R. Grace Chemical Manufacturing Facility. The project was the third in a series of three pilot-scale projects aimed at validating Daramend for use on various chlorinated organic pesticides.
Treatment of about 250 tons of soil impacted with various chlorinated pesticides including Toxaphene and DDT was conducted in a covered in situ treatment cell. The treatment process involved multiple cycles of the application of Daramend reagent to a 60 cm thick layer of soil within a treatment area.
The mean concentration of Toxaphene was reduced from 239 mg/kg to 5.1 mg/kg, respectively. The mean concentration of DDT was reduced from 89.7 mg/kg to 16.5 mg/kg. In heavily impacted areas of the treatment cell, the Toxaphene concentration was reduced from 1,600 mg/kg to 11mg/kg after eight treatment cycles, and to 5.1 mg/kg, or a 99.7% reduction, after 12 treatment cycles.