膨润土、褐煤及其混合添加对铅污染土壤钝化修复效应研究  

Immobilization and Remediation of Pb Contaminated Soil Treated with Bentonite, Lignite and Their Mixed Addition

作　　者：张静静[1] 赵永芹 王菲菲 化党领[1] ZHANG Jingjing;ZHAO Yongqin;WANG Feifei;HUA Dangling(College of Resources and Environment,Henan Agricultural University,Zhengzhou 450000,China)

机构地区：[1]河南农业大学资源与环境学院,河南郑州450000

出　　处：《生态环境学报》2019年第2期395-402,共8页Ecology and Environmental Sciences

基　　金：国家重点研发计划项目(2018YFD0800304);国家自然科学基金项目(41371311);河南省教育厅项目(18B210009);河南农业大学博士科研启动项目(30601643)

摘　　要：土壤重金属污染原位钝化修复是通过向土壤中添加一些钝化修复材料,通过溶解沉淀、离子交换吸附、氧化还原、有机络合等反应来改变土壤中重金属的赋存形态,降低土壤中重金属的生物有效性,在重金属污染修复中具有重要意义。为探究膨润土与褐煤单一及其复配材料对Pb污染土壤的钝化修复效果,以采自河南省济源市某铅冶炼企业周边0-20 cm表层重金属污染土壤为研究材料,设置盆栽玉米(Zea mays L.)试验,采用正交试验处理将膨润土(S)和褐煤(P)按1.5%、3%、5%的浓度梯度单独添加,以及将二者正交混合添加,采用BCR连续提取法研究不同钝化剂处理对Pb污染土壤的修复效应。结果表明,膨润土单一施用对土壤中Pb的有效态含量降低不明显,而褐煤的单一施用能显著降低土壤中Pb的有效态含量,其中添加5%褐煤的处理中弱酸提取态含量降幅达48.7%。膨润土与褐煤混合处理使土壤中Pb的弱酸提取态含量降幅达19.1%-50.8%,残渣态含量增幅达4.8%-40.5%,其中1.5%膨润土+5%褐煤的复配处理对Pb污染土壤的钝化修复效果最佳。膨润土与褐煤配施处理使玉米茎叶中Pb含量降幅为3.4%-33.7%,而膨润土与褐煤的单一钝化处理效果不明显。膨润土与褐煤单一及其配施处理均能显著降低玉米根中Pb含量,降幅为41.5%-66.0%,对玉米根部富集Pb有良好的抑制效果。褐煤单一施用对Pb污染土壤的钝化修复效果整体优于膨润土,两者配施的修复效果因其配施比例而异。In situ immobilization of heavy metal in contaminated soils with amendments can decrease the bioavailability of heavy metals by changing occurrence state of heavy metals in soils,caused by the reactions of dissolution/precipitation,exchange/adsorption,oxidation/reduction and organic complex.This method has been considered as a non-replaceable and important measure for contaminated soil remediation.In this work,pot experiments were conducted to investigate the effects of bentonite(S)and lignite(P)addition on immobilization and remediation of Pb contaminated soils sampled from Jiyuan City,Henan Province.The addition amounts of bentonite(S)and lignite(P)were 1.5%,3%,5%respectively,and the mixture treatment was based on the orthogonal experimental design.BCR(European Community Bureau of Reference)sequential extraction method was used to assess the remediation effects of amendments on soils polluted by Pb after incubation and seedling stage.The results indicated that adding lignite alone could significantly reduce the weak acid extractable content of Pb,while there was no significant difference by bentonite addition alone.Among lignite treatments,5%lignite treatment decreased the weak acid extractable content of Pb by 48.7%.The mixed treatment of bentonite(S)and lignite(P)worked well,which decreased the weak acid extractable content of soil Pb by 19.1%-50.8%,and increased the residual content of Pb by 4.8%-40.5%.The mixed treatment of bentonite(S)and lignite(P)reduced by 3.4%-33.7%of Pb content in stems and leaves in contrast to the CK,but bentonite(S)or lignite(P)alone made no difference.All the treatments,mixed addition or alone,can significantly reduce Pb content in roots by 41.5%-66.0%in contrast to the CK.For the immobilization and remediation effect,lignite treatment works better than bentonite treatment,and the effects of the combinations of these two amendments are different due to each proportion.

关 键 词：铅 膨润土 褐煤 钝化修复 玉米 土壤 

分 类 号：X53[环境科学与工程—环境工程]