摘要
为探究呼伦湖中As(砷)的时空变化格局及成因,分别于春季、夏季、秋季、冬季采集呼伦湖表层水和表层沉积物样品,对As的时空分布及其组成特征进行了调查,并探讨呼伦湖中As的来源及环境因素对水体As分布的影响.结果表明:①呼伦湖水体中ρ(TAs)(TAs为总As)在6.6~87.3μg/L之间,平均值为47.0μg/L,其中ρ(DTAs)(DTAs为溶解态TAs)占比为70.6%~99.8%,且As(Ⅴ)(砷酸盐)为主要存在形态.春季、冬季ρ(TAs)平均值高于夏季、秋季,且冬季ρ(TAs)的空间分布与其他3个季节差异明显.②表层沉积物w(TAs)为1.64~15.49 mg/kg,各季节w(TAs)空间分布均呈由西北向东南递减的趋势;w(F1)(F1为可交换态及碳酸盐结合态As)和w(F2)(F2为Fe/Mn氧化物结合态As)在w(TAs)中的占比相对较高,分别为31.7%和30.0%,一定环境条件下F1和F2易向水体迁移,是水体中As的主要来源.③呼伦湖水体pH、冬季冰封、入湖河流等环境因素均可影响水体中As的时空分布,其中冰封引起的沉积物-水界面缺氧环境及污染物浓缩效应是造成冬季湖泊西北沿岸水体ρ(TAs)显著升高的主要原因.研究显示,呼伦湖水体及沉积物中的As均以自然来源为主,其中沉积物释放及环境变化是水体中As时空分布格局的主要影响因素.
In order to explore the spatio-temporal pattern and the cause of arsenic(As)in Lake Hulun,surface water and sediment samples were collected in spring,summer,autumn and winter.The spatio-temporal distribution and component characteristics of As in Lake Hulun were investigated,and the As source as well as the influences of environmental factors on As distribution in water were analyzed.The results showed that:(1)Theρ(TAs)(TAs:total As)in Lake Hulun was between 6.6 and 87.3μg L,with an average value of 47.0μg L.ρ(DTAs)(DTAs:dissolved TAs)accounted for 70.6%-99.8%ofρ(TAs),and arsenate(As(Ⅴ))was the dominant species in the water.The averageρ(TAs)in spring and winter was higher than that in summer and autumn,and the spatial distribution ofρ(TAs)in winter was significantly different from the other three seasons.(2)The w(TAs)in the surface sediment ranged from 1.64 to 15.49 mg kg,and it showed a decreasing spatial distribution from the northwestern to southeastern parts of the lake.There were relatively high proportions of w(F1)(F1:exchangeable and carbonate bound As)and w(F2)(F2:Fe Mn oxides bound As)to w(TAs)(31.7%and 30.0%,respectively),indicating a high mobility of these As fractions into water under certain environmental conditions.They were the main source of As in water.(3)Environmental factors such as pH value,freezing period and river inflow affected the spatio-temporal distribution of As.Freezing-caused anaerobic environment at the sediment-water interface and the effect of pollutant concentration were the main reasons for the significant increase ofρ(TAs)in the water of the northwest coast of the lake during winter.The arsenic in the water and sediments of Lake Hulun mainly came from natural sources,and the release of As in the sediments and environmental changes were important factors influencing the spatio-temporal distribution of As in the water.
作者
车霏霏
君珊
陈俊伊
郭云艳
王书航
包文旗
CHE Feifei;JUN Shan;CHEN Junyi;GUO Yunyan;WANG Shuhang;BAO Wenqi(National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;State Environment Protection Key Laboratory for Lake Pollution Control,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Ecological Environment Monitoring Station of Hulunbeir,Inner Mongolia,Hulunbeir 021008,China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2021年第4期831-840,共10页
Research of Environmental Sciences
基金
国家自然科学基金项目(No.41907335)。
关键词
砷
时空变化
组成特征
环境因素
呼伦湖
arsenic
spatio-temporal changes
component characteristics
environmental factor
Lake Hulun
