生物炭-腐殖酸-磷酸盐联合修复土壤重金属Cd污染研究

Study on remediation of soil contaminated with heavy metal Cd by use of combination of biochar-humic acid-phosphate

近年来土壤重金属污染问题受到了社会广泛关注,这也与我国粮食安全和生态环境保护密切相关。腐殖酸和过磷酸钙复配在修复土壤重金属Cd污染中取得了良好效果,然而二者联合施用易造成土壤酸化。生物炭、腐殖酸和过磷酸钙是修复土壤重金属污染的常用材料,目前对3种钝化剂组合使用的效果评价研究甚少。采用牛粪和玉米秸秆两种生物炭与腐殖酸和过磷酸钙复配,研究了其对土壤pH、重金属形态以及修复效果的影响,结果表明:生物炭、腐殖酸和过磷酸钙的联合配施,可明显提高土壤的pH,使土壤中重金属Cd的有效态质量分数降低了51.62%,修复后土壤中的Cd主要以较稳定的可氧化态和残渣态形式存在。

The issue of heavy metal contaminated in soil has attracted increasing attention from communities,which is closely related to domestic food security and ecological protection.Promising results has been obtained from the combination of humic acid and superphosphate in remediation of soil contaminated with heavy metal Cd.However,the combined application is likely to cause soil acidification.Biochar,humic acid and superphosphate are widely used separately for remediation of heavy metal pollution in soil,but little research work has been done on evaluation of the results from combined application of the three deactivators.The effects of the biochar composed of cow manure and corn straw,blending with humic acid and superphosphate on soil pH,heavy metal patterns,and remediation efficiency were studied.The results show that the combined application of biochar,humic acid,and superphosphate in remediation significantly increased soil pH,lowered the content of heavy metal Cd in the soil by 51.62%.After remediation,the occurrence of Cd in the soil mainly represented by stable oxidizes and residuals.