高炉矿渣与磷酸盐复配材料对Cu、Pb、Zn污染土壤的钝化效果研究

Research on Passivation Effect of Compound Material of Blast Furnace Slag and Phosphate on Soil Contaminated by Cu,Pb and Zn

选取湖北某矿区重金属污染土壤,通过钝化实验和金属赋存形态分析实验探究了经高炉矿渣(BFS)及其与磷酸二氢钾(MKP)的复配材料修复前后重金属Cu、Pb、Zn的浸出毒性及赋存形态的变化情况。结果表明,BFS-MKP复配材料对土壤的钝化效果优于BFS单独处理,BFS-MKP复配材料对土壤中Cu、Pb的钝化效果要优于Zn,针对Cu、Pb的钝化效率最高分别达到86.1%与88.2%。此外,BFS-MKP复配材料可以促进土壤中活性较高形态的Cu、Pb向较稳定的形态转化。添加复配材料并养护28 d后,土壤中可交换态Cu、Pb含量占比可分别从16.6%、22.7%最低降至0.6%、4.3%,而残渣态Cu、Pb含量占比可分别从64.3%、41.7%最高升至89.3%、81.9%。

The heavy metal contaminated soil in a mining area of Hubei Province was selected.The leaching toxicity and speciation changes of heavy metals Cu,Pb and Zn before and after remediation by blast furnace slag(BFS)and its compound material with potassium dihydrogen phosphate(MKP)were investigated by passivation experiment and metal speciation analysis experiment.The results showed that the passivation effect of BFS-MKP compound material on soil was better than that of BFS alone.The passivation effect of BFS-MKP compound material on Cu and Pb in soil was better than that of Zn.The passivation efficiency of Cu and Pb reached 86.1%and 88.2%,respectively.In addition,the BFS-MKP compound material can promote the transformation of Cu and Pb with higher activity into more stable forms in the soil.After adding compound materials and curing for 28 days,the proportion of exchangeable Cu and Pb in soil can be reduced from 16.6%and 22.7%to 0.6%and 4.3%respectively,while the proportion of residual Cu and Pb can be increased from 64.3%and 41.7%to 89.3%and 81.9%respectively.