Typical Cases of Groundwater Pollution and Control Strategies for Closed Coal Mine in China

Abstract

Due to the coal resource depletion, complicated geological conditions, and policy adjustment of China coal mine industry, a large number of coal mines have been closed and abandoned. The rebound of groundwater level will cause flooding of goaf and roadways after mine closure. The hydrogeological conditions change significantly as well. The pollutants will leach out, transform and transport which lead to pollution and increase risk to the groundwater system in the mining area. This research investigated closed coal mining area in Xuzhou, Zibo, Fengfeng, Kaili, Yangquan, Doulishan, Huaibei, Jiaozuo, Jingxing, Mile, etc., to present typical cases for analyzing the featured pollutants in mine water. Eight groundwater pollution pathways were summarized in closed coal mines, including pollution infiltration from surface mining fissures; submerged water infiltration pollution; leaching pollution of surface solid waste; cross strata pollution from the diversion fissure zone in the mining roof; cross strata pollution through the mining fissures in the mining floor; cross strata pollution through the water-conducting wells; cross strata pollution of faults or collapse columns; water overflow from goaf. Three typical cases on cross strata pollution in the closed/abandoned coal mine were analyzed emphatically. Aiming at the prevention and control of groundwater pollution risk in coal mine, the technical ideas of reducing quantity and pollutant of mine water, channel blocking, extraction control, purification and utilization are put forward. Based on this idea, the main pollution prevention and control technologies are recommended, and the countermeasures for the environmental protection of groundwater in closed mine are proposed.

Source Apportionment and Health Risk Assessment of Heavy Metals in Karst Water from Abandoned Mines in Zhangqiu, China

“…Mine drainage has a serious impact on the groundwater environment, which not only pollutes the aquifer, but also has a negative impact on the groundwater environment, thereby seriously endangering the health and safety of residents [8][9][10]. Especially in recent years, the karst water produced by some abandoned coal mines will affect the local water resources and ecological environment [11,12]. Studying the health risk of heavy metal pollution in the groundwater around abandoned mines can help us understand whether the groundwater is seriously polluted by coal mining activities, thereby providing a basis for groundwater protection policies [13][14][15].…”

Identification of the Pollution Mechanisms and Remediation Strategies for Abandoned Wells in the Karst Areas of Northern China

“…Several types of abandoned wells exist, including coal mine abandoned wells [8,9], oil field abandoned wells [10], coal mine gas (natural gas) abandoned wells [11][12][13], geothermal abandoned wells [14,15], and abandoned water wells [6,16,17]. The primary aim of remediation for abandoned coal mine wells is to sever the hydraulic link between acid mine drainage and other aquifers, thereby preventing cross-layer pollution [18]. The primary aim of remediation for abandoned oil field wells is to prevent accidents-such as leakage, wellhead loss of control, and blowouts-that could cause environmental pollution.…”