Natural attenuation of geothermal arsenic from Yangbajain power plant discharge in the Zangbo River,Tibet, China |
| |
| Institution: | 1. Key Laboratory of Western China''s Environmental System (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China;2. State key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;3. CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China;4. Laboratory of Green Chemistry, Lappeenranta University of Technology, Mikkeli 50130, Finland;1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;3. College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000, China |
| |
| Abstract: | The Yangbajain geothermal field located in central Tibet is characterized by the highest measured reservoir temperature among all hydrothermal systems in China. The high-temperature geothermal fluid extracted from Yangbajain has been used for electricity generation for over 30 years. The geothermal wastewater generated by the Yangbajain power plants, with arsenic (As) concentrations up to 3.18 mg/L, drains directly into the Zangbo River, the major surface water at Yangbajain, which has elevated arsenic concentrations in the segments downstream of wastewater discharges. However, along the flow direction of the river, the arsenic concentration decreases sharply. Further inspection reveals that the concentrations of weakly bound arsenic, strongly adsorbed arsenic and total arsenic in riverbed sediment were affected by the drainage of geothermal wastewater, indicating that the sediment serves as a sink for geothermal arsenic. A logarithmic relationship between the integrated attenuation coefficients (IAC) for three river segments and the corresponding adsorption distribution coefficients of riverbed sediment samples also suggests that besides the dilution of geothermal arsenic in the Zangbo River, natural attenuation of arsenic may be caused by sorption to riverbed sediment, thereby reducing its health threat to local residents using the Zangbo River as a drinking water source. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
