黄土区煤矸石排矸场重金属污染风险分析及评价  

Risk Analysis and Evaluation of Heavy Metal Pollution of Coal Gangue Dumping Sites in Loess Areas

作　　者：张治国[1,2] 朱海东 郑永红 胡友彪[1] 马庆斌[1] 吴月 孔自豪 ZHANG Zhiguo;ZHU Haidong;ZHENG Yonghong;HU Youbiao;MA Qingbin;WU Yue;KONG Zihao(School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China;Academician Workstation in Anhui Province,Huainan 232001,China)

机构地区：[1]安徽理工大学地球与环境学院,安徽淮南232001 [2]安徽省院士工作站,安徽淮南232001

出　　处：《金属矿山》2024年第9期267-274,共8页Metal Mine

基　　金：“十三五”国家重点研发计划项目(编号:2020YFC1908601);安徽省院士工作站开放基金项目(编号:2022-AWAP-01)。

摘　　要：为了探究黄土区煤矸石长期堆存产生的重金属污染问题,以宁夏王洼煤矿排矸场煤矸石和土壤为研究对象,分析排矸场煤矸石和土壤的理化特性,测定煤矸石和底层土壤的重金属总量和有效态含量,并通过潜在生态风险指数法评估煤矸石堆积过程中存在的生态风险,明确底层土壤中潜在危害性突出的重金属元素。结果表明:(1)煤矸石和底层土壤均呈碱性,煤矸石堆底层10cm和20cm深度的土壤全盐量大于1.5g/kg,呈轻度盐化水平,煤矸石的堆存对接触土壤层的盐分累积有一定的贡献。(2)煤矸石底层土壤中Cr、Cu、Pb、Ni、Zn、Cd、As和Hg这8种重金属元素总量平均值低于宁夏土壤背景值。煤矸石中除As元素外7种重金属总量均高于底层土壤、对照点黄土和宁夏土壤背景值,在底层土壤中Cr、Cu、Pb、Ni和Zn这5种元素有效态含量均高于对照点黄土。(3)基于底层土壤中8种重金属元素总量评价,单元素潜在生态风险指数(E_(r)^(i))均低于40,综合潜在生态风险指数(RI)为85.83<150,重金属元素生态风险等级均为Ⅰ级低生态危害水平。因此,宁夏王洼煤矿排矸场煤矸石的露天堆存对底层土壤重金属元素含量产生累积效应,但重金属生态风险等级为轻微水平,其中Hg和Cd元素是主要的生态风险贡献因子。研究结果可以为半干旱黄土丘陵区煤矿固体废物安全堆存和环境生态修复提供理论指导。In order to explore spontaneous combustion and heavy metal pollution caused by long-term storage of coal gangue in loess areas,the coal gangue and soil in the Wangwa coal mine waste dump in Ningxia were taken as the research objects.The physicochemical characteristics of the coal gangue and soil in the dump were analyzed,and the industrial value and spontaneous combustion risk of coal gangue were evaluated.The total and effective content characteristics of heavy metals in coal gangue and bottom soil were analyzed,and the potential ecological hazards of heavy metals were evaluated through methods,Evaluate the ecological risks of heavy metals in soil caused by the accumulation process of coal gangue,and identify the potentially harmful heavy metal elements in the underlying soil.The results showed that:①both the coal gangue and the underlying soil are alkaline,and the total salt content of the soil with a thickness of 10 cm and 20 cm in the coal gangue pile is greater than 1.5 g/kg,showing a mild salinization level.The storage of coal gangue has a certain contribution to the accumulation of salt in the contact soil layer.②The average total amount of Cr,Cu,Pb,Ni,Zn,Cd,As and Hg in the bottom soil of coal gangue is lower than the background value of Ningxia soil.The total amount of 7 heavy metals in coal gangue,except for As element,is higher than the background values of the bottom soil,control point loess,and Ningxia soil.The effective content of Cr,Cu,Pb,Ni and Zn in the bottom soil is higher than that of the control point loess.③Based on the evaluation of the total amount of 8 heavy metal elements in the underlying soil,the single element potential ecological risk index(E_(r)^(i))is all below 40,the comprehensive potential ecological risk index(RI)is 85.83<150,and the ecological risk level of heavy metal elements is all at level Ⅰ with low ecological hazards.Therefore,the open-air storage of coal gangue in the Wangwa coal mine discharge site in Ningxia is not prone to spontaneous combustion.However,it can

关 键 词：煤矸石 土壤 重金属污染 生态风险 黄土区 

分 类 号：X53[环境科学与工程—环境工程]