柳江流域河流溶解态重金属时空分布及污染评价  

Spatial and Temporal Distribution and Pollution Evaluation of Soluble Heavy Metals in Liujiang River Basin

作　　者：张婉军 辛存林[1] 于奭[2] 刘齐 曾鹏 ZHANG Wan-jun;XIN Cun-lin;YU Shi;LIU Qi;ZENG Peng(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China;Key Laboratory of Karst Dynamics,Ministry of Natural Resources/Guangxi,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,China;Environmental Monitoring Station of Liuzhou City,Liuzhou 545001,China)

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070 [2]中国地质科学院岩溶地质研究所,自然资源部/广西岩溶动力学重点实验室,桂林541004 [3]柳州市环境保护监测站,柳州545001

出　　处：《环境科学》2021年第9期4234-4245,共12页Environmental Science

基　　金：地质调查项目(DD20190452);国家自然科学基金项目(41402324);中国地质科学院岩溶地质研究所基本科研费专项(2020004);国家重点研发计划项目(2016YFC0502302)。

摘　　要：在不同季节对露塘及洛维断面水体中可溶态重金属Zn、Al、Co、As、Ni、Cr、Cu、Mn、Pb、Hg和Cd进行高密度监测,进而研究可溶态重金属的时空分布及其污染来源,并利用内梅罗综合污染指数法对柳江水体环境质量进行评价.结果表明:(1)露塘和洛维断面可溶态Al、Co、As、Ni、Cr、Mn、Pb和Cd均符合国家地表水质量Ⅲ类标准,Zn和Cu重金属质量浓度远低于标准限值,Hg含量略有超标.柳江流域水体各重金属质量浓度大体呈现出平水期最高,丰水期最低的时间变化规律.在空间分布上洛维断面重金属质量浓度较高;(2)柳江流域重金属元素Hg、Cd和As单因子污染指数较高,内梅罗综合污染指数评估显示水体中重金属综合污染风险具有一定的季节变化特征表现(3月>11月>6月),指示不同季节变化对研究区饮水安全可能会存在一定隐患.露塘和洛维两个断面水体重金属总体属于中度污染水平,其中洛维断面污染程度相对较严重,应当优先列为柳江流域水环境管理部门的控制断面;(3)在探讨年际尺度与月降雨期重金属污染评价的区别中得出,当利用河流中的Cu元素质量浓度进行河流重金属评价时,降雨季与常规季节的选取对年际尺度河流重金属污染评价影响不显著,然而当河流中存在As、Mn、Pb、Al、Cr和Ni元素时将会造成年际尺度的河流重金属污染评价差异性显著;(4)多元统计分析结果显示,Cd、Cr、Ni、Co和Pb主要来源于工业生产活动;As和Zn主要来源于雨水淋溶生活污染废弃物;Mn、Al和Cu主要来源于农药和化肥的施用.In the Liujiang River,soluble heavy metals Zn,Al,Co,As,Ni,Cr,Cu,Mn,Pb,Hg,and Cd were monitored day and night to determine their temporal and spatial distribution as well as the sources of this pollution. The Nemerow comprehensive pollution index method was then used to evaluate the environmental quality of the Liujiang River water body. The results showed that:(1) For each river section( Lutang and Luowei),the amounts of soluble Al,Co,As,Ni,Cr,Mn,Pb,and Cd all met the Class Ⅲ water quality standard limit,as defined in the National Surface Water Quality Class Ⅲ Standard. The concentration of Zn and Cu was far below the standard limit,while the Hg content slightly exceeded the standard;the concentration of heavy metals in Liujiang River basin was highest in the normal season and lowest in the wet season. In terms of spatial distribution,the Luowei section had a higher heavy metal concentration.(2) The single factor pollution indexes for elemental Hg,Cd,and As were higher in the Liujiang River basin. The Nemerow comprehensive pollution index evaluation shows that the risk of heavy metal pollution in the water body exhibits certain seasonal variations( March > November > June),indicating that rainfall in different seasons may result in reduced drinking water safety in the study area. The water of the Lutang and Luowei sections generally exhibited a moderate level of heavy metal pollution. The comprehensive pollution index of the Luowei section was higher than that of the Lutang section,and the pollution level was relatively severe. Therefore,the Luowei section should be listed as a priority control section of the Liujiang River basin by the water environment management department;(3) After assessing the difference in heavy metal pollution between annual and monthly rainfall periods,it was found that the selection of rainy season or conventional season has no significant impact on the assessment of heavy metal pollution in rivers,when the mass concentration of Cu in the river is used. However,the presence of As,Mn

关 键 词：柳江流域 河流重金属 时空分布 污染评价 水质 

分 类 号：X522[环境科学与工程—环境工程]