某岩溶矿坑场地污染特征及潜在风险分析  

Pollution characteristics and potential risk analysis of a karst pit

作　　者：刘玲 郝社锋[1,2] 许伟伟 孟则坤[3] Liu Ling;Hao Shefeng;Xu Weiwei;Meng Zekun(Technology Innovation Center for Ecological Monitoring&Restoration Project on Land(Arable),Ministry of Natural Resources,Nanjing 210018,Jiangsu,China;Geological Survey of Jiangsu Province,Nanjing 210018,Jiangsu,China;Hohai University,Nanjing 211100,Jiangsu,China)

机构地区：[1]自然资源部国土(耕地)生态监测与修复工程技术创新中心,江苏南京210018 [2]江苏省地质调查研究院,江苏南京210018 [3]河海大学,江苏南京211100

出　　处：《地质学刊》2021年第1期90-99,共10页Journal of Geology

基　　金：中国地质调查局项目“全国矿产资源开发环境遥感监测”(121201003000172705)、“全国2017年新增的矿山恢复治理状况监测”(121201003000172718)、“苏南现代化建设示范区综合地质调查”(12120115043201);江苏省自然资源科技项目“面向土地综合整治的耕地质量评价与生态修复技术研究”(KJXM2019011)。

摘　　要：某灰岩矿坑场地受到了有机污染,对当地脆弱的岩溶地下水环境构成威胁。在查明场地周边岩溶发育特征的基础上,结合区域水化学、水动力场调查结果,分析了场地及周边地下水污染特征和污染场地的潜在风险。结果表明:场地内水体受到了萘、氯乙烯、苯酚、邻苯二甲酸二丁酯、PCB52等多种有机物的污染,其中以4-氯-3-甲基苯酚、2,4-二硝基苯酚等酚类化合物含量最高;场地内水体水质兼具地下水特征,水化学类型为Cl·SO_(4)-Na·Ca型,与其相邻的2个矿坑水质已受到影响,水体水化学类型往污染场地水体类型演化;场地周边地下水水质总体较好,仅场地西侧1个地下水井水质受到了污染矿坑的影响。目前,该矿坑场地仍处于水位漏斗恢复期,污染物并无向外迅速扩散的水动力条件,但当矿坑场地流场恢复至天然状态后,矿坑内污染物可通过场地周边的3条岩溶裂隙带-60 m标高以浅的地层向周边迁移,对环境造成了巨大威胁,应采取降低矿坑水位、定期监测矿坑水和地下水水质、实施帷幕灌浆工程等措施防控场地的潜在污染风险。A limestone mine site suffered from organic contamination,posing a potential threat to the vunerable karst groundwater.Based on the investigation of karst development characteristics around the site as well as the results of regional hydrochemistry and hydrodynamics,this paper analyzed the pollution characteristics of the groundwater in and around the study area and its potential risk.The results showed the groundwater in the study area was polluted by naphthalene,vinyl chloride,phenol,dibutyl phthalate,PCB52 and other organic substances,among which 4-chloro-3-methyl phenol and 2,4-dinitrophenol have the highest concentration.The water in the mine had the similar characteristics with the groundwater and its hydrochemical type is Cl·SO_(4)-Na·Ca.The water of the two karst pits close to the polluted area has already been polluted and its hydrochemical type is becoming similar to that of the polluted pit.In general,the quality of the groundwater around the study area is better,and only one groundwater well in the west of the site is affected by the polluted mine.The polluted pit site is still in the recovery period of water cone level and there is no hydrodynamic condition for pollutants to diffuse rapidly outward.But when the flow field of the site is restored to its natural state,the pollutants in the pit can transport to the surrounding area through 3 karst fissure zones(above-60 m)to shallow stratum,which poses a great threat to the local environment.Related authorities should take effective measures including reducing water level,regularly monitoring water level and groundwater quality,implementing curtain grouting project to fight against the potential pollution risk.

关 键 词：岩溶矿坑 岩溶地下水 有机污染 潜在风险 

分 类 号：P641.54[天文地球—地质矿产勘探]