HAZARDOUS-WASTE STABILIZATION WITH CLEAN-COAL TECHNOLOGY ASH RESIDUALS

Clean coal technology by-products, collected from commercial operation s under steady state conditions, are reacted at bench-scale with metal -laden hazardous wastes. Reaction conditions involve mixing calibrated weight ratios of by-product to hazardous waste with attention to mini mizing added moisture. Of the 15 heavy metals monitored, lead appeared to be the element of greatest concern both from a leaching and a regu latory point of view. While leaching information is focused on lead st abilization, similar information exists for other metals as well. Stab ilized solid products of reactions are sampled for TCLP evaluations. F or samples showing evidence of metal stabilization, further experiment ation was conducted evaluating optimum moisture content and developmen t of physical strength (measured as compressive strength) over time of curing. Results show that certain hazardous wastes are highly amenabl e to chemical stabilization, while others are not; certain by-products provided superior stabilization, but did not allow for strength gener ation over time. Copyright (C) 1996 IAWQ.