Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Key Laboratory of Mongolian Plateau Ecology and Resource Utilization, Ministry of Education, Hohhot 010021, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China.
Water and Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Huhhot 010018, China.
Sci Total Environ. 2022 Aug 20;835:155519. doi: 10.1016/j.scitotenv.2022.155519. Epub 2022 Apr 27.
Groundwater is the primary water source in coalfields under arid and semiarid climates. However, the problem of excessive concentrations of sulfate, which is a constant component in coalfields, and its potential health risks are often neglected in Northwest, China. To determine the groundwater quality, health threats, and driving forces of sulfate in coal mine groundwater, this study performed hydrochemical and isotopic analyses of 61 groundwater samples from a typical coalfield in northwestern China. We found that phreatic groundwater had lower total dissolved solid (TDS) and freshwater hydrochemical types (mainly Ca-HCO and Ca-Na + K-HCO types). In contrast, confined groundwater showed saline affinity (Na + K-SO type) and high TDS values, and the quality was unacceptable for drinking, with EWQI values larger than 100, which could be attributed to its high SO concentration. In addition, confined groundwater was also unsuitable for irrigation with high values of electric conductivity (EC), sodium absorption ratio (SAR), and Na%. Combining with isotopic analysis (δD, δO, δS and δO), the sulfate of confined and phreatic groundwater was controlled by gypsum dissolution and irrigation activities. As for public human health, SO poses potential non-carcinogenic risks to various populations, especially children. Therefore, the impact of geogenic and anthropogenic factors should be paid attention to, including the reduction of the use of sulfur-containing fertilizers and discharge of sulfur-containing sewage; and the water treatment should be carried out. Importantly, there is a need to adopt a strategy of water supply from multiple sources to ensure human health.
地下水是干旱半干旱气候下煤田的主要水源。然而，在中国西北地区，人们往往忽视了煤田中常量组分硫酸盐浓度过高的问题及其潜在的健康风险。为了确定煤矿地下水的水质、健康威胁和硫酸盐的驱动因素，本研究对中国西北地区一个典型煤田的 61 个地下水样本进行了水化学和同位素分析。研究发现，潜水具有较低的总溶解固体（TDS）和淡水水化学类型（主要为 Ca-HCO 和 Ca-Na + K-HCO 类型）。相比之下，承压水呈咸水特征（Na + K-SO 型）和高 TDS 值，且质量不可饮用，其 EWQI 值大于 100，这可归因于其高 SO 浓度。此外，由于电导率（EC）、钠吸收比（SAR）和 Na%值较高，承压水也不适用于灌溉。结合同位素分析（δD、δO、δS 和 δO），承压水和潜水的硫酸盐由石膏溶解和灌溉活动控制。就公众的人类健康而言，SO 对各种人群，尤其是儿童，构成了潜在的非致癌风险。因此，应注意关注地质和人为因素的影响，包括减少含硫肥料的使用和含硫污水的排放；应进行水处理。重要的是，需要采取多水源供水战略，以确保人类健康。
