不同浸提剂对污染河道底泥中重金属的浸出影响  

Effects of different extractants on heavy metals leaching in contaminated sediment

作　　者：闫怡新[1] 卢一富 高健磊[1] 吴建平[1] 李贝[1] 

机构地区：[1]郑州大学水利与环境学院,河南郑州450001 [2]济源市环境科学研究所,河南济源459000

出　　处：《环境污染与防治》2015年第6期74-78,共5页Environmental Pollution & Control

摘　　要：以某有色金属冶炼企业排放口下游河道底泥为研究对象,分别采用无机酸（盐酸、硫酸、硝酸）和有机酸（醋酸、柠檬酸、苹果酸和丁二酸）研究在不同酸性条件（pH为2~6）下Pb、Cd、Zn、Cu的浸出效果。结果表明,有机酸的浸提能力明显高于无机酸,且4种重金属的浸出浓度均随着pH的升高而迅速降低。对无机酸而言,当pH〉3时,重金属的浸出浓度趋于稳定;对有机酸而言,在pH为2~5的较大范围内,醋酸表现出较高的浸提能力,而柠檬酸对Pb和Cu没有明显的浸出效果。结合泥质特点,从重金属的络合、沉淀、水解、吸附等反应过程对其浸出特征进行了分析,同时提出醋酸良好的缓冲能力是其浸提效果优于其他有机酸的重要原因。Leaching properties of Pb,Cd,Zn,Cu at pH of 2-6using different inorganic acids（hydrochloric acid,sulfuric acid,nitric acid）and organic acids（acetic acids,citric acid,malic acid,succinic acid）aiming at polluted sediment at downstream of a non-ferrous metal smelting enterprise were discussed.Results showed that all the organic acids leached more heavy metals than inorganic acids did,and leaching concentrations of 4metals decreased with increasing pH.As to inorganic acids,the leaching concentration declined dramatically at pH of 2-3,and flattened out at pH〉3.As to organic acids,the acetic acid showed exceptional leaching ability in a wide pH range of 2-5,while citric acid did not show obvious leaching effect for Pb and Cu.Combined with the sediment features,analysis and speculation were made for leaching characteristics of the heavy metals in view of complexation,precipitation,hydrolysis and adsorption.It was also presented that the better buffer capacity of acetic acid induced the better leaching effect than other organic acids.

关 键 词：底泥 重金属 浸出 PH 柠檬酸 醋酸 

分 类 号：X52[环境科学与工程—环境工程]