喀斯特山区砷渣堆场污染迁移风险与区划  

Migration of pollution risk and zoning of arsenic slag site in Karst Mountainous Regions

作　　者：李泽群 李学先 段明宇 覃应机 雷琨[1] 张翅鹏[1,2] 韩志伟[1,2] 吴攀[1,2] 何守阳[1,2,3] LI Zequn;LI Xuexian;DUAN Mingyu;QIN Yingji;LEI Kun;ZHANG Chipeng;HAN Zhiwei;WU Pan;HE Shouyang(Key Laboratory of Karst Georesources and Environment of Ministry of Education,Guizhou University,Guiyang 550025;College of Resource and Environmental Engineering,Guizhou University,Guiyang 550025;Guizhou Karst Environmental Ecosystems Observation and Research Station,Ministry of Education,Guiyang 550025;College of Agriculture,Guizhou University,Guiyang 550025)

机构地区：[1]贵州大学喀斯特地质资源与环境教育部重点实验室,贵阳550025 [2]贵州大学资源与环境工程学院,贵阳550025 [3]贵州喀斯特环境生态系统教育部野外科学观测研究站,贵阳550025 [4]贵州大学农学院,贵阳550025

出　　处：《环境科学学报》2022年第3期457-467,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金委员会-贵州省人民政府喀斯特科学研究中心项目(No.U1612442);贵州省生态学国内一流学科建设项目(No.GNYL[2017]007)。

摘　　要：喀斯特山区土壤空间异质性强,污染物在洼地土壤之间可能通过独特的地表与地下二元水文地质结构的贯通互联而发生转移.通过对喀斯特山区砷渣堆场的废渣及受其影响的土壤中砷含量、分布和迁移等进行系统分析表明,降雨淋滤砷渣产生的废液随地表和地下径流远距离迁移影响洼地土壤;pH从渣场经麻厂到屯脚洼地沿迁移路径升高,均值分别为3.3、6.8、7.5;As含量沿线降低,分别为59.87、28.96、20.51mg·kg^(-1);洼地土壤多因排水条件差发生内涝淹没呈面状污染扩散展布.单因子和地累积指数评价结果显示:耕作层(0~30 cm)较下部土壤污染风险高,砷的垂向迁移致使耕作层底部污染趋增.砷通过洼地落水洞、漏斗排水与下渗经地下溶洞与管道发生长距离迁移,空间上呈现由“点”沿“线”成“面”的水平和纵向污染风险转移特征;区域上则形成点、线和面以及地表地下组合在水平和垂直方向上的非连续污染风险格局.研究结果对认识喀斯特山区土壤重金属污染风险格局及精准区划与修复提供新借鉴思路.Due to a higher spatial heterogeneity of soil in karst mountains,pollutants may transfer among karst depressions through the connection of the unique surface and underground dual hydrogeological structures The content,distribution and migration of arsenic in As-slag and polluted soil in karst mountain area were systemically investigated.The results show that arsenic leachate produced from slags by rainfall leaching migrates longdistance with surface and underground runoff,affecting the soil in depressions.The pH rises along the migration path from slag via Machang to Tunjiao depression,and the average value is 3.3,6.8,and 7.5,while the average content of arsenic decreases along path of runoff which is 59.87 mg·kg^(-1),28.96 mg·kg^(-1),20.51 mg·kg^(-1),respectively.The soil in depressions is mostly flooded by arsenic leachate and spread as non-point source pollution due to poor drainage conditions.The results of single factor and geoaccumulation index showed that the risk of soil pollution was higher in the tillage layer(0~30 cm)than in the lower part of the soil,and the vertical migration of arsenic led to the increase of soil pollution at the bottom of the tillage layer.Arsenic migrates long-distance through the depression sinkhole,funnel drainage and infiltration,the underground cave and pipeline,showing the characteristics of horizontal and vertical pollution risk transfer from"point"along the"line"to"plane"in space Regionally,a non-continuous pollution risk pattern is formed as points,lines and surfaces in horizontal and vertical directions,as well as combination of surface and underground.This project provides a potential insight to recognize risk pattern of soil heavy metal pollution in karst mountainous regions and precise zoning and restoration.

关 键 词：污染风险转移 异质性 风险区划 砷污染 喀斯特山区 

分 类 号：X53[环境科学与工程—环境工程]