Seasonal variations in sulfur isotopic composition of dissolved SO_4^(2-) in the Aha Lake, Guiyang and their implications  

作　　者：SONG Liuting LIU Congqiang WANG Zhongliang TENGYanguo WANG Jinsheng LIANG Lili BAI Li 

机构地区：[1]College of Water Sciences, Beijing Normal University, Beijing 100875, China [2]Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China [3]State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China

出　　处：《Chinese Journal Of Geochemistry》2011年第4期444-452,共9页中国地球化学学报

基　　金：supported by the Natural Science Foundation of China (Nos.40903008,90610037,40721002);the Open Research Fund of State Key Laboratory of Environmental Geochemistry,Chinese Academy of Sciences (SKLEG9006);the Chinese important special project (No.2009ZX07419-003)

摘　　要：The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42- in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42- and δ34S were de-veloped for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly ob-served in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and 834S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42 in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO4 2- and δ34S were developed for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly observed in epilirmtion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.

关 键 词：硫同位素组成 石膏溶解 季节变化 阿哈湖 贵阳市 硫酸盐还原细菌 浓度范围 硫化物氧化 

分 类 号：X513[环境科学与工程—环境工程] P641.12[天文地球—地质矿产勘探]