新疆阿克苏河流域高砷地下水化学特征及富集成因  

Hydrochemical characteristics and enrichment mechanisms of high-arsenic groundwater in the Aksu River Basin,Xinjiang

作　　者：鲁力 葛燕燕 李升 张云 LU Li;GE Yanyan;LI Sheng;ZHANG Yun(College of New Energy and Environment,Jilin University,Changchun 130000,Jilin,China;Institute of Water Resources and Environment,Jilin University,Changchun 130000,Jilin,China;College of Geology and Mining Engineering,Xinjiang University,Urumqi 830046,Xinjiang,China;Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)

机构地区：[1]吉林大学新能源与环境学院,吉林长春130000 [2]吉林大学水资源与环境研究所,吉林长春130000 [3]新疆大学地质与矿业工程学院,新疆乌鲁木齐830046 [4]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011

出　　处：《干旱区研究》2025年第2期258-273,共16页Arid Zone Research

基　　金：国家自然科学基金项目(U23A201007,U1603243)资助。

摘　　要：阿克苏河流域生活与灌溉用水20%来自地下水,了解该地区高砷地下水分布与形成至关重要。根据水化学和同位素结果,运用统计法与图解法分析地下水水化学特征、砷的空间分布与形态,结合地质地貌、水文地球化学过程揭示砷的赋存条件,研究典型剖面高砷地下水富集的影响因素与过程。结果表明:研究区单一结构潜水为碱性氧化性微咸水,承压水区潜水为碱性弱氧化性咸水、承压水为碱性还原性淡水;As含量在0.05~160μg·L^(-1),超标率为19.5%,高砷地下水水化学类型主要为Cl·SO_(4)-Na、SO_(4)·Cl-Na·Ca、Cl-Na型,主要分布在阿克苏河与台兰河中下游深度为10~42 m的承压水区潜水与承压水中;从山前倾斜平原到细土平原,潜水赋存环境变化为氧化-弱氧化-弱氧化偏还原,承压水处于还原环境;地下水As含量与饱和指数总体呈现逐步增大的趋势;单一结构潜水与承压水主要受水岩作用控制,承压水区潜水主要受蒸发浓缩控制;地下水As的分布主要与结构因素有关,自然来源主要为雌黄的溶解,干旱的气候、地质地貌、沉积环境为高砷地下水的富集创造外部条件,pH、脱硫酸作用、氧化还原电位(Eh)、地下水循环模式等影响As的释放与迁移。研究有助于了解阿克苏河流域高砷地下水的形成演化规律,对保证供水安全具有重要意义。In the Aksu River Basin,20%of the domestic and irrigation water comes from groundwater,making it crucial to understand the distribution and formation of high-arsenic(As)groundwater in the area.Based on the hydrochemical and isotope results,graphical methods were used to analyze the hydrochemical characteristics of the groundwater and the spatial distribution and forms of arsenic,revealing the As occurrence environment combined with geological,geomorphological,and hydrogeochemical processes.The results revealed that the singlestructure phreatic water is alkaline oxidizing brackish water,the phreatic water in the confined water area is alkaline weakly oxidizing saline water,and the confined water is alkaline reducing fresh water.The As content ranged from 0.05 to 160μg·L^(-1),with a rate exceeding the standard of 19.5%.The hydrochemical types of high-As groundwater are mainly Cl·SO_(4)-Na,SO_(4)·Cl-Na·Ca,and Cl-Na,distributed in confined and phreatic water in the area downstream of the Aksu and Tailan Rivers at a depth of 10-42 m.From the mountainfront to the fine soil plain,the occurrence environment changes from weakly oxidizing to reducing.The As content and saturation index of the groundwater generally exhibited an increasing trend.The single-structure phreatic water and confined water were mainly controlled by the water-rock interaction.In contrast,the phreatic water in the confined water areas was mainly controlled by the evaporation concentration.The distribution of groundwater As is mainly related to structural factors,with realgar dissolution being the primary natural source.The arid climate and the geological,geomorphological,and hydrogeological conditions create external conditions for the enrichment of high-As groundwater.Factors like pH,desulfurization process,Eh,and groundwater circulation patterns affect As release.This study helps us understand the formation and evolution of high-As groundwater in the Aksu River Basin,which is crucial for ensuring water supply safety.

关 键 词：阿克苏河流域 高砷地下水 干旱地区 成因分析 赋存环境 

分 类 号：P641.3[天文地球—地质矿产勘探]