SEPA United States Environmental Protection Agency EPA/540/M5-89/005 August 1989 SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION Demonstration Bulletin Solidification/Stabilization Process Soliditech, Inc. TECHNOLOGY DESCRIPTION: The Soliditech solidification/stabilization technology mixes hazardous waste materials in soils or sludges with pozzolanic material (cement, fly ash, or kiln dust), a proprietary additive called Urrichem, other proprietary additives, and water. The process is designed to aid in the physical and chemical immobilization of the hazardous waste constituents by binding them in a leach- resistant matrix. After the contaminated waste material is collected and screened to remove oversized material, it is introduced to a batch mixer. Each waste material is mixed with proprietary chemical reagents and additives, water, and cement. Figure 1 is a schematic of the process. u R R C H E Once thoroughly mixed, the treated waste is discharged from the mixer and allowed to harden. The treated waste is a solidified mass with significant unconfined compressive strength, high stability, and a rigid texture similar to concrete. Batch mixers of various capacities are available to treat different volumes of waste. WASTE APPLICABILITY: This technology is intended for the treatment of soils and sludges contaminated with organic compounds, metals, inorganic compounds, and oil and grease. DEMONSTRATION RESULTS: The Soliditech process was demonstrated December 5-8, 1988, at the Imperial Oil Company/Champion Chemicals Superfund site in Morganville, New Jersey. In the past, this location contained both chemical processing and oil reclamation facilities. Physical test results of the solidified waste samples were very good. Unconfined compressive strengths ranged from 390 to 860 psi. Wet/dry and freeze/thaw durability test results were excellent, showing no or very little weight loss after 12 cycles. Permeability of the treated waste was very low. TCLP extraction tests indicated reduced leaching of all metals except those contributed by the cement or other additives (aluminum, calcium, chromium, and sodium). No volatile organic compounds were detected in the TCLP leachates of the treated wastes. Several semivolatile organic compounds (phenols) were detected in the treated wastes that were either not present or present at lower concentrations in the untreated waste. The presence of these compounds has not been explained but may be due to a chemical reaction. Oil and grease was found to leach from the treated waste at the same or at slightly higher concentrations than from the untreated waste. Raw ------- waste contained from 2,000 to 50,000 times more oil and grease than leachates from the treated waste. Key findings from the Soliditech demonstration are summarized below. • Chemical analyses of TCLP, EP, BET, and ANS 16.1 leachates showed that heavy metals present in the untreated waste were immobilized by treatment. • The process solidified solid and liquid wastes with high organic content (up to 17%) containing oil and grease. • Volatile organic compounds were not detected in the treated waste and were assumed to be lost during waste collection, screening, and treatment. • Excellent physical properties were measured in the treated waste including low permeability, high unconfined compressive strength, and resistance to weathering. • Semivolatile organic compounds (phenols) were detected in the treated waste and the TCLP leachate from the treated waste; but not in the untreated waste or its TCLP leachate. • Oil and grease content of the untreated waste ranged from 2.8 to 17.3 percent. Oil and grease content of the solidified waste ranged from 4.6 to 7.7 percent. Oil and grease content of the TCLP leachate of both the untreated and treated wastes was in the 1.4 to 12 ppm range. • The solidified wastes increased in volume an average of 22 percent. The bulk density of the waste material increased by approximately 35 percent due to solidification. • The pH of the solidified waste ranged from 11.7 to 12.0. The pH of the untreated waste ranged from 3.4 to 7.9. • PCBs were not detected in any TCLP leachates, whether the waste was treated or not. • Visual observation of the broken pieces of the solidified waste showed the presence of dark inclusions approximately 1 mm in diameter, which may be untreated waste. Microstructural studies are ongoing. A technology Evaluation Report and an Applications Analysis Report describing the complete demonstration will be available in the Winter of 1989/1990. FOR FURTHER INFORMATION: EPA Project Manager: Walter E. Grube, Jr. U.S. EPA Risk Reduction Engineering Laboratory 26 West Martin Luther King Drive Cincinnati, OH 45268 513-569-7798 (FTS: 684-7798) BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 Official Business Penalty for Private Use $300 United States- Center for Environmental Research Environmental Protection Information Agency Cincinnati OH 45268 EPA/540/M5-89/005 ------- |