新疆农业大学学报

在新疆石河子地区采集了23组地下水样品,分析研究了其中Pb、Zn、Fe、Mn、Cr6+、Cd、Hg、As、Se共9项指标在空间上的分布特点及其影响因素。结果表明,除Pb和Cd外,其余7项指标均有检出。对照《生活饮用水卫生标准(GB5749-2006)》可知,As、Mn和Fe点位超标率分别为34.8%、8.7%和4.3%。地下水中重金属和类金属含量平面分布特征为:超标点集中分布在冲洪积平原的中部和下部,各指标含量及超标程度由冲洪积平原中部向下部递增。垂向分布特征为:潜水中重(类)金属含量普遍较低;Fe、Mn超标点分布于浅层承压水区;As超标点主要分布于深层承压水,且其点位超标率高于浅层承压水。潜水中重金属和类金属含量达到《地下水质量标准(DZ/T0290-2015)》Ⅲ类标准要求;受As、Fe、Mn含量超标的影响,承压水未能达到Ⅲ类标准要求。潜水属于轻污染,而承压水重(类)金属污染程度大于潜水。地下水中Fe和Mn主要来自含水介质中被分离出的含Fe和Mn的易溶盐,以及含水层原生质中含Fe、Mn的氧化物;As主要来自研究区内南部山区煤矿的煤层,以及多年来大量使用的化肥、农药污染物在土壤中的累积。地下水径流条件、氧化还原环境是影响Fe、Mn分布主要因素,此外酸碱环境也会影响As的分布。

The paper selects 23 groundwater samples in Shihezi area and analyzes spatial distribution characteristics and influence factors of 9indexes such as Pb,Zn,Fe,Mn,Cr6+,Cd,Hg,As and Se.The result showed that all the indexes had been detected except Pb and Cd.According to Drinking Water Sanitary Standard(GB5749-2006),the exceeding standard sampling rates of As,Mn and Fe were 34.8%,8.7%and 4.3% respectively.In horizontal direction of the study area,the plane distribution of heavy metals(metalloid)in underground water was characterized by:exceeding standard sampling sites were concentrated in the central and lower parts of the alluvial plain,and the content of each index and the degree of exceeding the standard increased from the central part of the alluvial flood plain to the lower part.In vertical direction of the study area,the distribution characteristic was that heavy metals(metalloid)contents in unconfined water were generally low,the exceeding standard sampling sites of Fe and Mn were distributed in shallow confined groundwater,the exceeding standard sampling sites of As were mainly distributed in deep confined groundwater,and the exceeding standard rate of As in deep confined groundwater was higher than that in shallow confined groundwater.Heavy metals(metalloid)contents in unconfined groundwater reachedⅢ class standard of Groundwater Quality Standard(DZ/T0290-2015),and contents in shallow and deep confined groundwater did not reach Ⅲ class standard.Unconfined groundwater was slightly polluted and confined groundwater was seriously polluted than unconfined groundwater.The Fe and Mn in groundwater were derived from iron and manganese soluble salt separated from aquiferous media,and iron and manganese oxides in aquiferous media.As was derived from coal seam of southern mountain coal mines and the accumulation of fertilizers,pesticides and pollutants in the soil over the years in the study area.The spatial distribution of Fe and Mn in groundwater in the study area was mainly affected by groundwater flow conditions and oxidation-deoxidation environment.In addition to the two factors,the spatial distribution of As was affected by acid-alkali environment,too.