Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China.
College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
Environ Sci Pollut Res Int. 2019 Mar;26(8):7442-7452. doi: 10.1007/s11356-019-04188-0. Epub 2019 Jan 29.
The Lhasa River basin is the economic and population center of Tibet and has abundant resources. Due to its harsh weather condition, high elevation, and inconvenient accessibility, few studies have focused on heavy metal distributions in this region. In the present study, to investigate the dissolved trace metal pollution and its controlling factors, 57 water samples from the Lhasa River and its tributaries were collected during three water flow regimes in 2016. The data on the dissolved fraction revealed that the Lhasa River basin appeared to have no to low pollution levels. However, the Lhasa River water showed alkaline characteristics which may affect the presence of heavy metal elements in a dissolved fraction. The concentration of heavy metal elements in colloidal or particulate matter therefore needs attention. Multivariate analyses were performed to determine the significant relationship between the data and to identify controlling factors for dissolved heavy metals in the study area. The results suggested that Mn, Cd, Cu, and Zn originated from a natural geological background, whereas Pb originated from mining drainage and As was influenced by geothermal flows. The concentration of dissolved heavy metals in the Meldromarchu tributary was greatly affected by the mining drainage water, while that in the Tölungchu tributary was greatly influenced by the geothermal water sources. This paper provides the first comprehensive analysis of dissolved heavy metal pollution characteristics and the controlling factors of pollution during the three different water flow regimes of the Lhasa River basin.
拉萨河流域是西藏的经济和人口中心，拥有丰富的资源。由于其恶劣的气候条件、高海拔和交通不便，很少有研究关注该地区的重金属分布。本研究旨在调查拉萨河及其支流的溶解痕量金属污染及其控制因素，于 2016 年三个水流时期采集了 57 个水样。溶解组分的数据表明，拉萨河流域似乎没有或低污染水平。然而，拉萨河水呈碱性特征，这可能会影响溶解组分中重金属元素的存在。因此，需要关注胶体或颗粒物质中重金属元素的浓度。进行了多元分析以确定数据之间的显著关系，并确定研究区溶解重金属的控制因素。结果表明，Mn、Cd、Cu 和 Zn 来源于自然地质背景，而 Pb 来源于采矿排水，As 受地热水流影响。梅尔东曲支流中溶解重金属的浓度受采矿排水的影响很大，而托尔曲支流中溶解重金属的浓度受地热水源的影响很大。本文首次全面分析了拉萨河流域三个不同水流时期的溶解重金属污染特征及其污染控制因素。
