Cr(VI)污染土壤及建筑物修复技术小试

STUDY ON THE REMEDIATION OF Cr(VI) CONTAMINATED SOIL AND SOLID WASTE

以某化工厂Cr(VI)污染土壤及建筑物为研究对象,分别开展了污染土壤柱洗脱、药剂修复和污染建筑物浸洗小试实验。结果表明:1)污染土壤柱洗脱实验经过6 d运行后,土壤中残留的Cr(VI)含量较低,为28.5 mg/kg,此时洗脱固液比约为1∶4,洗脱效率可达97%;2)修复污染土壤中,FeSO_4和CaS_5两种药剂对Cr(VI)污染土壤的修复均具有一定的效果,FeSO_4+CaS_5混用的情况下,可在降低药剂投加量的情况下,大幅降低土壤中TCr和Cr(VI)的浸出浓度以及土壤的Cr(VI)含量,铬的稳定性增强,迁移性降低;3)破碎后的污染建筑物经1次清水+1次药剂浸洗后,浸洗效果较好。

The paper investigated the chromium contaminated soil and solid waste from a chemical plant. A pilot test was performed to treat a chromium contaminated soil by using column eluting and remediation, and a chromium contaminated solid waste by using washing process. The results showed that： 1） The concentration of Cr（VI） in eluted soil was 28.5 mg/kg after 6 days, the solid-to-liquid ratio was 1∶4, and the removal rate of total Cr（VI） was 97%. 2） Two agents could effectively and rapidly decrease total Cr（VI） content in the short term. Mixing two agents could reduce dosing quantity, and the leaching concentrations of total Cr and Cr（VI） significantly decreased by increasing the dosaged of FeSO4＋CaS5. 3） The washing process could divide into two steps： firstly washing with water and secondly with agents. The concentrations of Cr（VI） in solid waste were below detection limits after washing.