Use of Sorbent Materials for Treating Hazardous Waste

Abstract

Abstract : The Department of Defense (DoD) spends millions of dollars each year to dispose of hazardous liquid wastes from military facilities. The Defense Logistics Agency (DLA) alone spent $23 million during fiscal year 1994 to dispose of 64 million pounds of liquid hazardous materials. This cost figure encouraged the DLA to find a better and cheaper disposal solution. Recognizing that industry uses sorbent materials to absorb chemical and oil spills in industry, the DLA thought these materials could also be used to treat liquid hazardous wastes. Therefore, through an Environmental Security Technology Certification Program (ESTCP) funding, DLA tasked the National Defense Center for Environmental Excellence (NDCEE) under an existing contract managed by the Army Armament Research and Development Energy Center (ARDEC) Industrial Ecology Center (IEC) to evaluate sorbents for this purpose. The NDCEE is operated by Concurrent Technologies Corporation (CTC), a non-profit organization headquartered in Johnstown, Pennsylvania. Hazardous waste disposal is expensive. If liquid hazardous wastes could be effectively treated by sorbents, cheaper sanitary landfill facilities could be used. This project sought to identify, demonstrate and validate a simple, efficient and cost-effective technology based on sorbents. Three representative DoD wastes were chosen for investigation: paint wastes, degreasing solvents, and acidic electroplating waste. Following preliminary screening, six classes of non-biodegradable sorbents were tested: non-biodegrabable peat, non-encapsulating polymeric, encapsulating polymeric, zeolitic, clay, and cellulosic. Bench-scale investigations on surrogate wastes showed: (1) waste acids containing heavy metals (nickel, cadmium, chromium, lead and zinc) up to 100 ppm could be rendered non-hazardous using treated clay sorbents; (2) no sorbent acceptably treated ignitable paint-related waste; and (3) no sorbent acceptably treated chlorinated solvent degreasing waste.