多雄藏布河水中溶解态砷的来源及其衰减机制  

Sources and natural attenuation of dissolved arsenic in Dogxung Zangbo River

作　　者：闫雅妮 张俊文 张东 赵志琦 YAN Yani;ZHANG Jun-wen;ZHANG Dong;ZHAO Zhiqi(School of Earth Science and Resources,Chang’an University,Xi’an 710054,China;College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]长安大学地球科学与资源学院,西安710054 [2]上海海洋大学海洋科学学院,上海201306

出　　处：《生态学杂志》2024年第6期1799-1806,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41930863);陕西自然科学基金项目(2022JZ-19和2022JQ-229)资助。

摘　　要：青藏高原地区部分河水As含量异常,对当地居民的身体健康有潜在威胁。为了进一步查明高原地区河水中As的来源及其衰减机制,本研究采集了多雄藏布流域11件河水样品,3件热泉样品,2件湖水样品和1件雨水样品,分析了样品中的As含量。结果表明:热泉样品中As的质量浓度高达9000μg·L^(-1)以上;两件湖水样品的As浓度分别为14.1和93.8μg·L^(-1);河水样品的As浓度为0.83~177μg·L^(-1)(平均值45.5μg·L^(-1)),其中64%的样品超过10μg·L^(-1);而雨水样品的As浓度低于0.1μg·L^(-1);富As热泉是研究区河水溶解态As的重要来源,其他来源贡献较小;从上游至下游,稀释作用、河流悬浮物或沉积物对As的吸附和共沉淀作用是河水溶解态As自然衰减的重要机制;这些相对富集As的悬浮物或沉积物随河流搬运至下游沉积,可能会导致下游地区沉积物及地下水中As含量异常,进而影响当地居民饮水安全。Some of rivers on the Qinghai-Tibet Plateau have high dissolved arsenic(As)levels,posing a potential threat to the health of local residents.To identify the sources and natural attenuation of dissolved As in the rivers,we analyzed the dissolved As concentrations in 11 river water samples,3 hot spring samples,2 lake water samples,and 1 rainwater sample collected from the Dogxung Zangbu River.Results showed that As concentration in the hot spring samples was up to more than 9000μg·L^(-1).The As concentrations in the two lake water samples were 14.1 and 93.8μg·L^(-1),respectively.The As concentrations of river samples ranged from 0.83 to 177μg·L^(-1)(mean 45.5μg·L^(-1)),with 64%of the samples exceeding 10μg·L^(-1).The As concentration of rainwater sample was below 0.1μg·L^(-1).The As-rich hot springs were an important source of dissolved As in river water,while other sources contributed less.From upstream to downstream,dilution,adsorption,and co-precipitation of As by river suspended matter or sediments are important processes for the natural attenuation of dissolved As in river water.These As-enriched river suspended matters or sediments are transported downstream and deposition,which may lead to high As levels in sediments and groundwater in downstream regions,thus affecting the drinking water safety of local residents.

关 键 词：青藏高原 河水 砷 热泉 

分 类 号：X52[环境科学与工程—环境工程]