4A沸石对土壤铅浓度及形态的影响

Effect of 4 A-Type Zeolite on Soil Pb Concentration and Form Changes

采用室内土柱淋洗培养法研究了4A沸石对土壤重金属铅浓度与形态变化的影响。结果表明,4A沸石对土壤重金属铅具有一定的钝化效果,可有效抑制土壤铅的迁移及生态有效性。未添加4 A沸石土壤经过淋洗培养后土壤铅的可交换态、碳酸盐结合态和铁锰氧化态铅浓度上升,有机结合态和残渣态铅浓度显著下降,37 d淋洗培养后土壤中铅以可交换态为主,所占比例为52.9%;而添加4 A沸石可有效降低土壤可交换态、碳酸盐结合态和铁锰氧化态铅的浓度,土壤铅以残渣态为主,其占比例44.8%～59.2%。

A soil column leaching cultivation method indoor was permormed to understand the effects of 4 A-type zeolite on heavy metal Pb in soil concentration and form changes.The results show that,4 A-type zeolite had some passivation effects on the migration and ecological validity of soil Pb.（1）Compared with the control,added 0.5 mg/kg,1.0 mg/kg and 2.0 mg/kg 4 A-type zeolite to soil,the soil Pb content decreased respectively about 45.3%,84.5% and 88.7%.（2）The soil Pb form changes evident,the exchanged state,carbonate state and Fe-Mn oxide combined state soil Pb concentration rise;organic combined state and residual state soil Pb concentration decreased significantly after leaching cultivation the soil.（3）Added the 4 A-type zeolite can effectively reduce the exchanged state,carbonate state and Fe-Mn oxide combined state soil Pb concentration.Compared with the control,the bioavailability（the sum of exchangeabl state,ecarbonate state and Fe-Mn oxide combined state soil Pb concentration） soil Pb concentration decreased 44.7%～55.1%;others（organic combined state and residual state soil Pb concentration） soil Pb concentrations increased significantly after 37 days of leaching cultivation.（4）After leaching cultivation,soil Pb without adding 4 A-type zeolite were mainly exist as exchanged state,is taken up proportion by 52.9%;the soil Pb adding 4 A-type zeolite were mainly exist as residual state,it＇s proportion is 44.8%～59.2%.