农林基质生物炭联合香根草对铜镉铅复合污染土壤的修复研究

Remediation of Soil Contaminated by Copper,Cadmium and Lead Combined with Agroforestry Matrix Biochar and Vetiveria zizanioides

通过盆栽试验,分析添加稻壳生物炭(DBC)、椰壳生物炭(YBC)和玉米秸秆生物炭(JBC)对土壤基本性质、土壤Cu、Cd和Pb的形态分布及香根草各部位Cu、Cd和Pb含量的影响。结果表明:单施生物炭及生物炭联合香根草处理均提高了土壤pH值和有机质含量,土壤脲酶、蔗糖酶和过氧化氢酶活性均有不同程度的升高;单施生物炭及生物炭联合香根草处理后,土壤中Cu、Cd和Pb总量降低;培养3个时间段内,土壤中可利用态Cu和Pb占比降低,残渣态Cu和Pb占比增加,残渣态Cd占比先减少后增加;添加生物炭显著降低了香根草根部重金属Cu、Pb、Cd的累积。生物炭有利于香根草将Cu、Cd、Pb稳定在根部,降低土壤中Cu、Cd、Pb的有效态,可应用于Cu、Cd、Pb复合污染土壤的修复治理。

The effects of adding rice husk biochar(DBC),coconut husk biochar(YBC)and corn stalk biochar(JBC)on the basic soil properties,the morphological distribution of Cu,Cd and Pb in soil,and the contents of Cu,Cd and Pb in different parts of Vetiveria zizanioides were studied by pot experiment.The results showed that both biochar application alone and biochar combined with V.zizanioides treatment increased soil pH value and organic matter content,and soil urease,sucrase and catalase activities increased to varying degrees.The total amount of Cu,Cd and Pb in soil decreased after biochar application alone or combined with V.zizanioides treatment.During 3 incubation periods,the proportion of available Cu and Pb in soil decreased,the proportion of residual Cu and Pb increased,and the proportion of residual Cd first decreased and then increased.The addition of biochar significantly reduced the accumulation of Cu,Pb and Cd in V.zizanioides root.Biochar is beneficial to the stabilization of Cu,Cd and Pb in the root of V.zizanioides and reduce the effective state of Cu,Cd and Pb in soil,and can be applied to the remediation of soil contaminated by Cu,Cd and Pb.