Acid based separation process for remediation of lead contaminated firing range soils

摘要

The removal of lead and other heavy metals present in an active US Army small arms firing range soil was evaluated in a pilot scale test program at Ft. Polk, Louisiana. Two different acid based extraction processes in conjunction with conventional physical separation methods were used. Physical separation processes consisting of screening and gravity operations removed most of the coarse lead particulates and slugs. Hydrochloric acid leaching followed by precipitation of lead as hydroxide recycledclean soil containing less than 500 mg/L total lead and less than 5 mg/L TCLP lead. Lead extraction efficiency with hydrochloric acid was 96 percent. The results of lead removal by physical separation in conjunction with acetic acid leaching were notconsistent over the whole test period and the total soil processed.