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SUPERFUND TREATABILITY CLEARINGHOUSE: FINAL REPORT: DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM FOR WASTEWATER LAGOONS PHASE II - SOLVENT EXTRACTION LABORATORY TESTING
Citation:
Environmental Science and Engineering, Inc. SUPERFUND TREATABILITY CLEARINGHOUSE: FINAL REPORT: DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM FOR WASTEWATER LAGOONS PHASE II - SOLVENT EXTRACTION LABORATORY TESTING. U.S. Environmental Protection Agency, Washington, DC, EPA/540/2-89/009, 1989.
Impact/Purpose:
to inform the public
Description:
The U.S. Army surveyed innovative treatment techniques for restoration of hazardous waste lagoons and selected solvent extraction as cost-effective restoration for further study. This treatability study focuses on treatment of organic (explosive) contaminated lagoon sediments which are the result of munitions production operations. Primary contaminants of concern included the following explosives: TNT, DNT, RDX and Tetryl. This was a laboratory study of solid extraction where the solvent is used in excess and the effectiveness of a single contact is limited by the ability to physically separate the liquid and soil fractions. The treatability goal is to reduce explosive contaminant level to 10 mg/kg. OPERATIONAL INFORMATION; Sediments tested were obtained from Navajo Army Depot (AD), AZ (predominantly volcanic cinders); Ft. Wingate AD, NM (mostly clay); and Louisiana Army Ammunition Plant. Explosive content of sediments ranged from 0.1-99/K and moisture content ranged from 23.8-42.8£. (Report provides characteristics information on sediments.) Acetone was selected as the leaching agent based on the solubility of contaminants, cost, and availability. Laboratory tests included: solubility, leaching efficiencies, and settling tests. Solubility tests evaluated water/acetone ratios to determine optimum operational range for individual contaminants and mixtures. Leaching tests evaluated effectiveness of countercurrent extraction to determine contact time required for equilibrium of explosives between leachate and the sediments. Multiple leaching tests were performed by shaking sediment with acetone/water mixture in 1-liter graduated cylinders for 30 minutes followed by solid-liquid separation. Settling tests were performed on two soils with significant solid content to determine settling rate to aid in design of waste water treatment unit.