DETERMINING THE OPTIMUM RATIO OF FLY ASH AND QUICK LIME FOR CR(VI) IMMOBILIZATION OF ARTIFICIALLY-CONTAMINATED SOIL

摘要

In the present study, a stabilization technology was applied to immobilize hexavalent chromium in artificial contaminated soils. The process is a chemical-physical treatment in which the toxic pollutants are physically entrapped within a solid matrix using chemical reactions that reduce its ability to dissolve into surrounding groundwater and, therefore, the toxicity risk is reduced. The objective of the treatment was to identify the optimum ratio between fly ash and lime in order to treat artificial soils contaminated with 0.4% of Cr (VI). The degree of chromium release from the soil was evaluated using a modified Toxicity Characteristic Leaching Procedure (TCLP) test from the US Environmental Protection Agency (EPA) and must be lesser than 5 ppm.