Reduction and Stabilization Remediation of Hexavalent Chromium (Cr6+)-Contaminated Soil

Hexavalent chromium (Cr6+)-contaminated soil samples were obtained from an electroplating workshop in Jingjiang, China. Then, the Cr6+-contaminated soil was processed using reduction and stabilization methods. Six reducing agents with different remediation abilities with respect to Cr6+ contamination (iron, SSL, FeSO4, Na2HSO3, Na2S2O3, and Na2S) were tested. The most efficient reducing stabilizing agent was FeSO4; which efficiency varied with the pH, with the optimum pH being neutral or near neutral. Lastly, the effects of acidified ferrous sulfate as a reducing agent, cement as a curing agent, and the combined use of dyeing were tested. Increases in the cement content and curing age led to a marked improvement in the curing effect on the Cr6+-contaminated soil.