某硫铁矿区废水池沉积物剖面中重金属化学形态分布和环境污染评价  

Speciation distribution and environmental pollution assessment of heavy metals in sediments from wastewater pond of a pyrite mine

作　　者：钟桥辉 王煜煊 任世兴 周玉婷 吴洋 殷美玲[3] 韦旭东 白秀明 王津[3] 张兆峰[1] 刘娟[3] ZHONG Qiaohui;WANG Yuxuan;REN Shixing;ZHOU Yuting;WU Yang;YIN Meiling;WEI Xudong;BAI Xiuming;WANG Jin;ZHANG Zhaofeng;LIU Juan(State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Science,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;Innovation Center and Key Laboratory of Waters Safety&Protection in the Pearl River Delta,Ministry of Education,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]中国科学院广州地球化学研究所同位素地球化学国家重点实验室,广州510640 [2]中国科学院大学,北京100049 [3]广州大学珠江三角洲水质安全与保护教育部重点实验室,广州510006

出　　处：《地球环境学报》2020年第5期524-535,共12页Journal of Earth Environment

基　　金：国家自然科学基金项目(41573008,41873015);广东省自然科学基金项目(2017A030313247);广州大学青年拔尖人才项目(BJ201709);第17届“挑战杯”全国大学生课外学术科技作品竞赛。

摘　　要：矿山开采是造成环境重金属污染的重要途径,揭示重金属在污染区的富集特征及潜在生态效应对重金属污染防治有重要意义。以粤西某硫铁矿区废水池沉积物剖面为研究对象,采用电感耦合等离子质谱仪和分级提取法分析底泥中Tl、Cr、Ni、Co与Cd总量和各化学形态的分布特征及生态风险,并结合矿物组成分析阐明富集及迁移机制。结果表明:底泥中Cd含量远超我国土壤背景值,且Cd主要以弱酸可交换态的形式存在;Tl含量同样远超我国土壤背景值,以残余态的形式为主;Cr和Ni含量均略高于我国土壤背景值,也主要以残余态的形式存在;Co含量小于我国土壤环境背景值,具有较大的弱酸可交换态比例。综合富集因子法和风险评价指数分析,底泥中Cd具有很强的环境潜在危害性;Tl具有强的环境潜在危害性;Cr和Ni具有中等程度的环境潜在危害性;Co没有环境潜在的危害。硫铁矿区废水池底泥是重金属(Cd、Tl、Ni和Cr)重要的汇和潜在二次污染源。硫铁矿区废水池底泥中Cd和Tl高度富集,Ni和Cr具有低—中等程度的富集,废水池底泥的污染防治与资源回收同样值得思考关注。Background,aim,and scope Mining/smelting is one of the important anthropogenic activities leading to heavy metal pollution in the environment.It is critical to investigate the enrichment characteristics and potential ecological effects of heavy metals in polluted areas for the prevention and control of pollution.In a pyrite mining area in western Guangdong,the wastewater produced by the separation and cleaning process of pyrite was discharged into a wastewater pond along a ditch.When the pond was full,the water overflowed into the stream,merged into Nanshan River,and finally entered Xijiang River.Herein,the contents,the main mineral composition and chemical fractionation of heavy metals in a sediment profile from the pyrite wastewater pond were studied.Materials and methods A sediment core with a total length of 30 cm was taken using a column sampler(6 cm in diameter)from the wastewater pond in the pyrite area.The sediment core was divided into 0—2 cm,2—4 cm,4—18 cm,18—24 cm and 24—30 cm,respectively,depending on the color distinction.The sediment samples were air-dried to a constant weight.The dried sediment samples were ground in an agate mortar and sieved to obtain<2 mm fractions,then well homogenized for further analysis.The main elements in the sediment samples were tested by X-ray fluorescence.The samples were characterized by semi-quantitative X-ray diffraction for analyzing mineralogical compositions.To determine the total heavy metal contents,the sediment samples were digested using a mixture of concentrated HNO3,HF,and HClO4 on a hotplate at 150℃.The chemical fractionation of heavy metals were analyzed using sequential extraction IRMM(Institute for Reference Materials and Measurements).All the samples were finally measured with high precision inductively coupled plasma mass spectrometry(ICP-MS,Perkin-Elmer,Elan 6000).Results The X-ray diffraction results showed that the bulk mineralogy of the sediments was dominated by quartz,muscovite,kaolinite and iron oxides(such as goethite,magnetite),wi

关 键 词：废水池底泥 重金属 分级提取 环境污染评价 

分 类 号：X703[环境科学与工程—环境工程]