KH_(2)PO_(4)和硅肥对垃圾填埋场紫色土重金属的钝化  

Passivation of Heavy Metals in Waste Landfills by KH2PO4 and Silicon Fertilizer

作　　者：龚正 黄丽[1] GONG Zheng;HUANG Li(National Key Laboratory of Soil Health Diagnosis and Green Remediation for Environmental Protection,Huazhong Agricultural University,Wuhan 430000,PRC)

机构地区：[1]华中农业大学国家环境保护土壤健康诊断与绿色修复重点实验室,湖北武汉430000

出　　处：《湖南农业科学》2022年第12期43-49,58,共8页Hunan Agricultural Sciences

基　　金：国家重点研发计划项目资助(2019YFD1100503)。

摘　　要：以四川省盐亭县云溪镇垃圾填埋场的紫色土为研究对象,选择KH_(2)PO_(4)(0.5%、1%或2%)和硅肥(1%或2%)为钝化剂,分别将其添加至土壤中培养30~60 d,探究典型酸碱性钝化剂对垃圾填埋场重金属污染紫色土的修复效果。结果表明:对比GB 15618—2018,土样中Cd超标0.82~2.13倍;BCR连续提取法和DTPA有效态提取法显示,土样中Cd、Pb具有较高的活性。经过60 d的钝化培养,2%KH_(2)PO_(4)对Cd、Pb的固定率最高分别为74.29%、39.97%;1%硅肥处理对Pb的固定率为32.67%;KH_(2)PO_(4)和硅肥提升了土壤有效P含量,同时使土壤pH值从8.5左右变为8.01、9.42。经2%KH_(2)PO_(4)钝化60 d后,酸溶态Cd的比例下降26.74%,提升了Cd的稳定性;2%KH_(2)PO_(4)与1%硅肥对Pb的形态转化程度接近,残渣态Pb的占比最高提升至36.44%,有效提升了Pb的稳定性。总体来说,KH_(2)PO_(4)和硅肥的最佳添加量分别为2%、1%,60 d时均可较好地钝化土壤中的Cd、Pb。Taking purplish soil of the waste landfill in Yunxi Town,Yanting County,Sichuan Province as the research object,passivators KH_(2)PO_(4)(0.5%,1%or 2%)and silicon fertilizer(1%or 2%)were added separately into the soil for 30-60 days incubation to explore the remediation effect of the passivators on the heavy metal contaminated purplish soil.Compared with GB 15618-2018,Cd in the soil samples exceeded the standard by 0.82-2.13 times;the BCR sequential extraction procedure and DTPA extraction method found Cd and Pb in the soil samples showing high activities.After 60 days of passivation,the highest fixation rates of Cd and Pb by 2%KH_(2)PO_(4)were 74.29%and 39.97%,respectively,and the fixation rate of Pb by 1%silicon fertilizer treatment was 32.67%;KH_(2)PO_(4)and silicon fertilizer increased the Olsen-P content in the soil,at the same time,changed the soil pH from around 8.5 to 8.01 and 9.42,respectively.After 2%KH_(2)PO_(4)passivation for 60 days,the proportion of Cd-F1 decreased by 26.74%,and the stability of Cd improved correspondingly;2%KH_(2)PO_(4)and 1%silicon fertilizer had a similar degree of transformation to Pb,and maximally increased the proportion of Pb-F4 to 36.44%,which effectively improved the stability of Pb.In general,the optimal addition amounts of KH_(2)PO_(4)and silicon fertilizer are 2%and 1%,respectively,which can passivate Cd and Pb in the soil well on the 60th day.

关 键 词：KH_(2)PO_(4) 硅肥 垃圾填埋场 紫色土 钝化 

分 类 号：S146.1[农业科学—肥料学]