不同施磷水平对土壤中重金属镉的钝化效果评价  

Evaluation on Passivation Effect of Cadmium in Soil Under Different Phosphate Fertilizers Levels

作　　者：周佚群[1] 梁成华[1] 杜立宇[1] 魏樵 

机构地区：[1]沈阳农业大学土地与环境学院,辽宁沈阳110866

出　　处：《水土保持通报》2014年第6期68-72,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"农业部农产品产地土壤重金属污染治理与修复"(31171997)

摘　　要：通过室内培养试验,以P/Cd摩尔配比分别为0,2∶3,3∶2,2∶1,4∶1进行了不同磷肥钝化修复Cd污染土壤试验。采用毒性淋溶提取法(TCLP)和形态分析法评价了磷酸氢二铵(DAP)、磷酸二氢钾(MPP)、过磷酸钙(SSP)和磷酸钙(TCP)对污染土壤中Cd的钝化效果。结果表明,4种磷肥的钝化效果依次为:MPP>DAP>SSP>TCP,4种磷肥的钝化处理可显著降低土壤中TCLP提取态Cd含量,在磷肥剂量水平P/Cd为4∶1时对土壤中Cd的钝化效果最佳,最大降低幅度为49%;添加磷肥能够大幅度提高土壤中速效磷的含量,相同磷水平下,土壤中速效磷含量高低次序为:MPP>DAP>SSP>TCP,TCLP提取态Cd含量随土壤速效磷含量升高而显著降低(R=-0.903**);DAP,MPP,SSP和TCP处理后交换态Cd的浓度降幅分别为23.75%,39.06%,16.60%和18.36%,而碳酸盐结合态(WSA)、铁锰氧化物结合态(Fe-Mn-OX)、有机结合态(OM)和残渣态(RES)Cd的含量均有所升高,表明磷素是通过改变Cd的存在形态而降低其有效态含量的。Cultivation experiments were conducted to evaluate the efficiency of four phosphate fertilizers in- eluding DAP（diammonium phosphate）, MPP （mono potassium phosphate）, SSP （calcium superphosphate） and TCP（triealeium phosphate） as stabilizing agents of Cd in contaminated soils. Five molar ratios of P/Cd were tested：0, 2 ： 3, 3 ： 2, 2 ： 1, 4 ： 1. The toxicity characteristic leaching proeedure（TCLP） and sequen- tial extraction methods were used to evaluate the efficiency. The results showed that four phosphate fertiliz- ers all could effectively reduce soil TCLP extractable Cd concentrations with the stabilization efficiency as MPP〉DAP〉SSP〉TCP. The most effective dose with greatest Cd reduction was 4 ： 1 of P ： Cd ratio, the most reduction was 49% Additions of all tested phosphate fertilizers can greatly improve the soil available phosphorus concentration with the concentration as MPP〉DAP〉SSP〉TCP at the same level of P, TCLP extractable Cd concentration were significantly negatively correlated with soil available phosphorus concen- tration（R=-0. 903＊ ＊ ） ; The decline of exchangeable Cd concentrations in DAP, MPP, SSP, and TCP trea- ted soils was respectively 23.75%, 39.06%, 16. 60% and 18.36%, but increased the Cd in WSA,OX, Fe- Mn-OM and RES. It indicates that Cd in soil can be adsorbed by phosphate fertilizers, reducing the bioavail- ability of Cd.

关 键 词：钝化修复 毒性淋溶提取法(TCLP) 磷肥 Cd 污染土壤 

分 类 号：X53[环境科学与工程—环境工程]