This paper describes research on a technique for removing lead from soil using 4-6 M chloride solutions at pH 4. Two soils were studied in this work: (1) a high-silt, high-clay, lead battery recycling site (LBRS) soil and (2) a high-sand LBRS soil. Testing determined that a batch-extracting process using chloride solutions reduced the lead in the high-silt, high-clay soil from 67,400 to 1,500-2,000 mg/kg and in the high-sand soil from 14,400 to 600 mg/kg. Both treated soils passed the EPA's Toxicity Characteristic Leachate Procedure test. In addition, concentrated chloride solutions were as effective as both EDTA and HCl at removing lead from the high-silt, high-clay soil. The ability of chloride solutions to remove lead as efficiently as EDTA while providing easy recovery of the chloride-complexed lead illustrates the viability of the process. [References: 29]
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