Comparison of Two Leaching Tests to Assess the Effectiveness of Cement-Based Hazardous Waste Solidification/Stabilization


Abstract: The Turkish Hazardous Waste Control Regulation (THWCR) recognizes solidification/stabilization (S/S) as a promising new technology for the safe disposal of hazardous wastes. In this study, the effectiveness of S/S in terms of the reduction of contaminant mobility was evaluated through two different leaching procedures. Heavy metal enriched mining residue was used as hazardous waste. For the S/S of mining waste, Portland cement as a binding agent was mixed with mining waste at different ratios (10 and 20\%). Solidified samples were crushed into two different fractionation sizes (between 1 and 2 mm and greater than 2 mm) and subjected to the toxicity characteristic leaching procedure of the U.S. Environmental Protection Agency and the distilled water leaching procedure of the THWCR. The leaching test results showed that generally S/S produced efficiencies greater than 90\% for the retention of metals in the solidified mass.

Keywords: Heavy metals, Leaching, Mining waste, Portland cement, Solidification/stabilization

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