生物炭和磷肥复合修复有色矿区重金属污染土壤的效果

REMEDIATION EFFECT OF COMBINATION OF BIOCHAR AND PHOSPHORUS FERTILIZER ON CONTAMINATED SOIL IN NONFERROUS METAL MINE

以有色矿区污染土壤为研究对象,考察了生物炭和磷肥单施及复合施用对土壤重金属的钝化修复效果。单施生物炭或与磷肥复合处理土壤pH显著升高。单施磷肥及与生物炭复合处理显著提高了土壤TCLP提取态磷。生物炭和磷肥是较好的钝化土壤中Pb、Zn和Cd的修复材料,尤以P+HB处理的效果最好,使土壤TCLP提取态Pb、Zn和Cd分别降低39.4%、18.3%和41.8%,降低了重金属的迁移性和生物有效性。Pb的酸可提取态和可还原态主要向残渣态转化,而Zn和Cd主要向可氧化态转化。生物炭和磷肥复合对污染土壤中Pb、Zn和Cd的钝化有协同作用。

The remediation effects of biochar and phosphorus fertilizer on contaminated soil in nonferrous metal mine were determined. Using biochar separately or combined with phosphorus fertilizer produced significant increase in soil pH. The leachability of phosphate in the TCLP extract from the soil increased significantly after using phosphorus fertilizer separately or combined with biochar. Biochar and phosphorus fertilizer are ideal immobilization amendments for soil contaminated by Pb,Zn and Cd. The combination of biochar and phosphorus fertilizer achieved the best results,decreasing mobility and bioavailability of heavy metals. The acid soluble fraction and reducible fraction of Pb were mainly transformed to the residual fraction,however,the two fractions of Zn and Cd were mainly transformed to the oxidisable fraction. The combination of biochar and phosphorus fertilizer produced cooperative effect on the immobilization of Pb,Zn and Cd in contaminated soil.