重金属和有机氯农药在沈阳郊区农田土壤中的吸附和迁移  

Sorption and transportation of heavy metals and organochlorine pesticides in agricultural soils from a Shenyang suburb

作　　者：赵兴敏[1,2] 王春玲[2] 董德明[1] 花修艺[1] 任建锋[1] 高明[1] 

机构地区：[1]吉林大学环境与资源学院,长春130012 [2]吉林农业大学资源与环境学院,长春130118

出　　处：《环境科学学报》2010年第9期1880-1887,共8页Acta Scientiae Circumstantiae

基　　金：国家重点基础研究发展计划(973)项目(No.2004CB418505)~~

摘　　要：采用静态吸附和土柱淋溶实验研究了重金属和有机氯农药在沈阳郊区农田土壤中的迁移转化规律.吸附实验结果表明,土壤对Pb和Cd阳离子的吸附大于对Cr(VI)和As(V)阴离子的吸附,对Cr(VI)的吸附大于对有机氯农药六六六(BHC,包括α-BHC、β-BHC、γ-BHC、δ-BHC)和滴滴涕(DDT,包括o,p'-DDT、p,p'-DDT)的吸附能力.土柱淋溶实验结果表明,Cr(VI)和As(V)在耕层土壤中的迁移速度远大于Pb、Cd的迁移速度,α-BHC由于淋溶液初始浓度较低,因而迁移速度较慢.淋溶实验后,具有较高生物可利用性和迁移性的可交换态重金属的相对含量增加了1.2%～5.4%,从而增加了Pb、Cd、Cr和As等重金属对生态系统的威胁.结合吸附和迁移实验结果可知,所研究污染物中,Cr(VI)和As(V)对地下水的威胁较大,Pb和Cd对农业生产的威胁较大,而目前有机氯农药已被国家明令禁止使用,土壤中的部分残留有机氯农药由于土壤的吸附作用,使得其对农业生产的威胁逐渐减小,对地下水的威胁性也较小.Sorption and vertical transportation of heavy metals and organochlorine pesticides in agricultural soils from Shenyang suburb were investigated in this work.The results of adsorption experiments showed the sorbed amounts of Pb2 ＋ and Cd2 ＋ were greater than those of anionic Cr（VI） and As（V）,and the amounts of Cr（VI） sorbed by the soils were greater than that of organochlorine pesticides.Soil column leaching tests indicated that the breakthrough speed of Cr（VI） and As（V） in agricultural soil was much higher than that of Pb,Cd,and due to low initial concentration of leaching solution the migration speed of α-BHC was slower.In addition,the breakthrough speed of Cr（VI） was greater than that of As（V）.For heavy metals,the proportion of exchangeable fraction with higher bioavailability and mobility were increased by 1.2% to 5.4% after the leaching tests,which increased the risk of Pb,Cd,Cr and As in the ecological system of the soils.Combining the results of sorption and vertical transport,anthropogenic Cr（VI） and As（V） pose the greatest risk to groundwater among all the pollutants studied,while anthropogenic Pb and Cd pose the greatest risk to agricultural production.However,organochlorine pesticides have been prohibited by the state and residual organochlorine pesticides in soils should be gradually,degraded,which will reduce the risk of organochlorine pesticides to agricultural production and groundwater.

关 键 词：农田土壤 重金属 有机氯农药 吸附 迁移 

分 类 号：X142[环境科学与工程—环境科学]