摘要
为明晰内蒙古阿拉善盟吉兰泰盐湖盆地浅层地下水污染特征及评估地下水饮水安全风险等级,采集了盐湖盆地研究区土壤表层(0—10 cm)样品56个,地下水样品127个,检测分析土壤中重金属元素Cu、As、Pb含量及水样中Cr、Hg、As、F^(-)、NO_(2)^(-)、NO_(3)^(-)含量.运用地下水风险评价概念模型,将地下水脆弱性、地下水污染物容量及土壤毒性污染物潜在生态危害评价有机结合,对地下水污染风险展开评价.借助ArcGIS软件进行克里格插值绘图,探析盐湖盆地浅层地下水风险的空间分布特征.结果表明:盐湖盆地地下水脆弱性指数范围为4.80—5.30属于中等脆弱性,吉兰泰盐湖东南部和吉兰泰镇西北部脆弱性高于其他区域;地下水样品中重金属Hg的含量在《地下水质量标准》中Ⅲ类水水质标准范围内,其他元素均有超标现象,其中F^(-)超标率最高,为62.20%,Cr、As、F^(-)、NO_(2)^(-)、NO_(3)^(-)变异系数分别为125.40%、183.50%、178.70%、248.70%、280.70%,属于强变异性,受外界因素干扰较为明显,研究区地下水特征污染物分布较为集中,主要分布在盐湖盆地的东南部;土壤中重金属Cr、Hg、As的平均含量分别为26.32、0.17、11.77 mg·kg^(-1),与内蒙古当地土壤背景值相比较,Cr的平均值在背景值范围内,而Hg、As的平均值分别超出背景值4.25、1.57倍,土壤综合潜在生态危害指数为188.32,属于中等潜在生态危害,在盐湖盆地中有41.07%的样品点属于中等、强、很强潜在生态危害;盐湖盆地地下水污染风险等级分布不同与含水层脆弱性指数、特征污染物容量指数及潜在生态危害指数有关,较高污染风险区和高风险区分布在锡林高勒镇西部,较高风险以上的面积占研究区面积的25.77%,古拉本敖包镇、贺兰山的东南部在中风险范围内,中风险区面积占研究区面积的11.49%.
In order to clarify the chemical pollution characteristics of shallow groundwater in Jilantai Salt Lake Basin,Alxa League,Inner Mongolia,and to assess the safety risk level of groundwater drinking water,56 samples of soil surface(0—10 cm)and 127 samples of groundwater in the Salt Lake Basin were collected to detect and analyze typical heavy metals in soil.The content of elements Cu,As,Pb and the content of Cr,Hg,As,F^(-),NO_(2)^(-),NO_(3)^(-)in the water sample.By using a conceptual model of groundwater risk assessment,the groundwater fragility,the capacity of groundwater toxic pollutants,and the potential ecological risk hazards of soil toxic pollutants are organically combined to carry out key assessments of groundwater pollution risks.Using ArcGIS software to perform Kriging interpolation mapping,the spatial distribution characteristics of shallow groundwater risk in the Salt Lake Basin were analyzed.The results show that the groundwater vulnerability index in the salt lake basin ranges from 4.80 to 5.30,which belongs to medium vulnerability,and the vulnerability of the southeast of Jilantai Salt Lake and the northwest of Jilantai Town is higher than that of other areas;The content of heavy metal Hg in groundwater samples is within the standard range,and other elements are beyond the standard.Among them,F^(-)exceeds the standard rate of 62.20%in the sample.The coefficients of variation of Cr,As,F^(-),NO_(2)^(-),and NO_(3)^(-)are respectively.It is 125.40%,183.50%,178.70%,248.70%,and 280.70%,which belong to strong variability and are obviously interfered by external factors.The distribution of groundwater characteristic pollutants in the study area is relatively concentrated,mainly in the southeast of the Salt Lake Basin;The average contents of heavy metals Cr,Hg,and As in the soil were 26.32,0.17,and 11.77 mg·kg^(-1).Compared with the local soil background value in Inner Mongolia,the average value of Cr was within the range of the background value,and the average value of Hg and As exceeds the background value by 4.25 and 1.57 times.The soil comprehensive potential ecological hazard coefficient is 188.32,which belongs to the medium potential ecological hazard,and 41.07%of the sample points in the Salt Lake Basin belong to the medium,strong and very strong potential ecological hazard;The uneven distribution of groundwater pollution risk in the Salt Lake Basin is related to the aquifer vulnerability index,characteristic pollutant capacity index and potential ecological hazard index.,the higher pollution risk area and the high risk area are distributed in the west of Xilingaole Town,and the area above the higher risk accounts for 25.77%of the regional area.The southeastern part of Gulaben Aobao Town and Helan Mountain is in the medium risk range,and the medium risk area accounts for 11.49%of the regional area.
作者
苑林枫
卢俊平
高瑞忠
张琦
黄磊
田雅楠
YUAN Linfeng;LU Junping;GAO Ruizhong;ZHANG Qi;HUANG Lei;TIAN Yanan(Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot,010018,China;Water Resources Protection and Utilization Key Laboratory,Inner Mongolia Agricultural University,Hohhot,010018,China)
出处
《环境化学》
CAS
CSCD
北大核心
2024年第2期536-548,共13页
Environmental Chemistry
基金
内蒙古自治区科技计划攻关项目(2019GG141)
内蒙古自治区教育厅科技英才项目(NJYT22040)
青年教师科研能力提升基金
内蒙古农业大学大学生科技创新基金(KJCX2020018)资助。
关键词
盐湖盆地
地下水
污染评价
空间分布
毒性污染物
salt lake basin
groundwater
pollution assessment
spatial distribution
toxic pollutants
