Current situation and forecast of environmental risks of a typical lead-zinc sulfide tailings impoundment based on its geochemical characteristics  

作　　者：Tao Chen Zi-Ang Yan Damao Xu Minghui Wang Jian Huang Bo Yan Xianming Xiao Xunan Ning 

机构地区：[1]SCNU Environmental Research Institute,Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety&MOE Key Laboratory of Environmental Theoretical Chemistry,South China Normal University,Guangzhou 510006,China [2]School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510640,China [3]State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China [4]China University of Geosciences,Beijing 100083,China

出　　处：《Journal of Environmental Sciences》2020年第7期120-128,共9页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Plan(No.2018YFC1802803);Guangdong Provincial Science and Technology Program(No.2015B020237003);the 2017 Central Special Fund for Soil,Preliminary Study on Harmless Treatment and Comprehensive Utilization of Tailings in Dabao Mountain(18HK0108)。

摘　　要：The potential environmental implications of a Pb(Lead)-Zn(Zinc)sulfide tailing impoundment were found to be dependent on its geochemical characteristics.One typical lead-zinc sulfide tailing impoundment was studied.Ten boreholes were set with the grid method and 36 tailings were sampled and tested.According to the results of metal content analysis,the tailing samples contained considerably high contents of heavy metals,ranging from 6.99 to 89.0 mg/kg for Cd,75.3 to 602 mg/kg for Cu,0.53%to 2.63%for Pb and 0.30%to 2.54%for Zn.Most of the heavy metals in the sample matrix showed a uniform concentration distribution,except Cd.Cd,Pb,Zn,and Mn were associated with each other,and were considered to be the dominant contributors based on hierarchical cluster analysis.XRD,SEM and XPS were employed for evaluation of the tailing weathering characteristics,confirming that the tailings had undergone intensive weathering.The maximum potential acidity of the tailings reached 244 kg H2SO4/ton;furthermore,the bioavailability of heavy metals like Pb,Cd,Cr,Cu,and Zn was 37.8%,12.9%,12.2%,5.95%,and 5.46%respectively.These metals would be potentially released into drainage by the weathering process.Analysis of a gastrointestinal model showed that Pb,Cr,Ni and Cu contained in the tailings were high-risk metals.Thus,control of the heavy metals’migration and their environmental risks should be planned from the perspective of geochemistry.

关 键 词：Pb-Zn tailings impoundment Geochemical characteristics Distribution of the metals Weathering process Environmental risk assessment 

分 类 号：X142[环境科学与工程—环境科学]