Cao Qingyi, Yang Liu, Qian Yahui, Chen Siyao
College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
Sichuan Water Conservancy Vocational College, Chengdu, 611230, China.
Environ Sci Pollut Res Int. 2023 Jan;30(3):7786-7800. doi: 10.1007/s11356-022-22530-x. Epub 2022 Aug 31.
Under the pressure of water shortages, coal mine water has been allocated as a national water resource in China. However, the existence of harmful trace elements (HTEs) in coal mine water causes environmental risks and health concerns over its reuse. Through a lixiviation experiment, the dominant factors affecting the dissolution of HTEs in coal were simulated and analyzed, and the environmental risks of HTEs in coal mine water in China were evaluated for the first time. The average dissolved content levels of HTEs from coal were Mn > Cu > Zn > Ni > Ba > Cr > Co > V > Mo > Se > U > Pb > Cd, and the average maximum dissolution rates were Ni > Co > Mo > Zn > Cu > Cd > Mn > Se > Ba > Cr > U > Pb > V. Oxidation-reduction potential (Eh) and pH are the dominant factors controlling HTE dissolution. Higher oxygen exposure levels induce Eh and pH development, resulting in more HTE dissolution. This study constructed the dissolution potential index (F) of HTEs from coal. Based on the results of the F model, the areas with the highest migration potential and environmental risk of HTEs from coal seams to mine water are located in southern China, especially in the southwest, followed by areas of eastern Inner Mongolia and Shanxi and Shaanxi provinces. The corresponding risks in other regions are relatively low; thus, mine water utilization remains an effective option. This study provides an effective reference for the analysis of HTE enrichment in coal mine water and an evaluation of its safe utilization.
在中国水资源短缺的压力下，煤矿水已被列为国家水资源。然而，煤矿水中有害微量元素（HTEs）的存在给其再利用带来了环境风险和健康隐患。通过淋溶实验，模拟并分析了影响煤中有害微量元素溶解的主要因素，并首次对中国煤矿水中有害微量元素的环境风险进行了评估。煤中有害微量元素的平均溶解含量水平为锰＞铜＞锌＞镍＞钡＞铬＞钴＞钒＞钼＞硒＞铀＞铅＞镉，平均最大溶解率为镍＞钴＞钼＞锌＞铜＞镉＞锰＞硒＞钡＞铬＞铀＞铅＞钒。氧化还原电位（Eh）和pH值是控制有害微量元素溶解的主要因素。较高的氧气暴露水平会导致Eh和pH值升高，从而使更多的有害微量元素溶解。本研究构建了煤中有害微量元素的溶解潜力指数（F）。基于F模型的结果，煤层中有害微量元素向矿井水迁移潜力和环境风险最高的区域位于中国南方，尤其是西南部，其次是内蒙古东部以及山西和陕西省地区。其他地区相应的风险相对较低；因此，矿井水利用仍然是一个有效的选择。本研究为分析煤矿水中有害微量元素的富集情况及其安全利用评估提供了有效的参考。
