乌梁素海盐度变化对沉积物重金属有效性的影响  

Impacts of Salinity Change on the Effectiveness of Heavy Metals in the Sediment of Wuliangsuhai

作　　者：吕杰 李畅游[1] 贾克力[1] 张生[1] 史小红[1] 赵胜男[1] 孙标[1] LV Jie;LI Changyou;JIA Keli;ZHANG Sheng;SHI Xiaohong;ZHAO Shengnan;SUN Biao(Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018

出　　处：《生态环境学报》2017年第9期1547-1553,共7页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(51509133;51339002;51669022;2016MS0406;NJZC13092)

摘　　要：乌梁素海内源污染源底泥释放的重金属对其水生态环境影响较大,为探索沉积物重金属在不同盐度条件下的释放规律以及沉积物中重金属总量、形态含量、迁移性大小及自身性质、沉积物理化性质对沉积物中重金属释放的影响,于2010-2016年每年8月采集18个水体样品,现场测定水体盐度,并在2016年8月采集10个表层沉积物样品测定沉积物重金属总量,采用BCR逐级提取法对沉积物中重金属Cu、Pb、Zn和Cr的4种形态进行提取,并进行静态释放试验以分析其在不同盐度浓度条件下的释放特征,监测和实验结果表明,乌梁素海水体盐度在2010-2016年8月期间逐年增大,呈现出由淡水湖向微咸水湖转变的趋势。重金属的总量、形态含量及其迁移性大小影响沉积物中重金属的释放量,沉积物中Cu、Pb、Zn和Cr的形态含量均以残渣态为主,其中Pb的残渣态含量最多,总量和释放量均最少,重金属酸可提取态含量较少,重金属迁移性的大小为Zn>Cu>Pb>Cr,而Zn的释放量大小与其在沉积物中的迁移活性及总量呈正相关关系。同时沉积物有机质含量、p H及含水率也均可影响沉积物重金属的释放,其中Pb的金属性最弱,溶解度相应较低,释放量最少。随着盐度的增加,沉积物中Zn、Cu和Pb释放量增加,Cr的释放量则先增大后减小,虽然4种重金属释放量虽然均较小,但其释放量增幅变化很大,存在较大的湖泊水生态环境风险。Heavy metals released from the sediment of endogenous source in Ulansuhai have a great impact on its aquatic environment.To get a better understanding on the release mechanism and effect factors,lake water was sampled yearly at18selected sampling points in the lake in August from2010to2016.The top layer sediments were sampled at10sampling points in August2016.The contents of the heavy metals were analyzed and four species of Cu,Pb,Zn,and Cr were extracted by the BCR step method.A static reaction was carried out to determine the release characteristics of the heavy metals from the sediments under different salinity conditions.The results showed that the salinity of Ulansuhai water was increasing from2010to2016,which showed a trend from the freshwater lake to the brackish water lake.The release amount of the heavy metals form the sediments were affected by the total content,species content,and migration ability of the heavy metals.The species contents of Cu,Pb,Zn,and Cr were mainly in residual,in which the residual state of Pb was the most,as a result of this,its total and release amounts were the least.The contents of the heavy metals in the sediments were less extractable.The mobility of the heavy metals was Zn>Cu>Pb>Cr.The release amount of Zn was positively related to its migration activity and total amount in the sediments.The release amounts of the heavy metals form the sediments were also affected by the organic matter content,pH,and water content of the sediments,in which Pb has the weakest metallicity with lower solubility and minimum release amount.With the increase of the salinity in the sediments,the release amounts of Zn,Cu,and Pb increased,while the release amount of Cr represented decreased when the salinity increased to a certain extent.Although the release rates of the heavy metals from the sediments were relatively less,there was a great increase in the release amount with the increase of the salinity.This indicated that there might be a greater risk on the lake water ecological environment.

关 键 词：沉积物 重金属 盐度 释放 

分 类 号：X131.2[环境科学与工程—环境科学]