Leachability and Physical Stability of Solidified and Stabilized Sludge from Dye Effluent Treatment

795-799Stabilization/Solidification (S/S) is used as a pre-landfill waste treatment technique that aims to make hazardous wastes safe for disposal. Cement based S/S technique is widely used because it offers assurance of chemical stabilization for many contaminants and produces a stable form of waste. Textile Sludge (TS), Furnace Slag (FS) and Fly Ash (FA) were used as stabilizing agents to substitute Ordinary Portland Cement (OPC) at 5 to 20 %. Copper Slag (CS) was used for replacement of fine aggregate with 20%. The solidified specimens were tested for compressive strength and heavy metal fixation. A total of 9 out of 16 proportions were more than the allowable compressive strength. With the least percentage of cement content, a compressive strength of 20 N/mm2 was obtained with 7.5 % TS, 7.5 % FS, 15 % FA and 70 % cement content with 20% CS as a replacement for fine aggregate. Toxicity Characteristics Leaching Procedure (TCLP) on processed concrete cubes were performed to evaluate the leaching ability of heavy metal of concrete cubes. The major heavy metals, chromium and iron were effectively reduced after solidification process to a concentration of 1.2 mg/L and Below Detectable Limit (BDL) in TCLP leachate which was within the US EPA regulatory limit