Earth Science Frontiers ›› 2021, Vol. 28 ›› Issue (5): 1-14.DOI: 10.13745/j.esf.sf.2021.2.8

Previous Articles     Next Articles

Pollution assessment and source apportionment of shallow groundwater in Suzhou mining area, China

ZHAO Weidong1(), ZHAO Lu1, GONG Jianshi2, ZHOU Wenyi1, QIAN Jiazhong1,*()   

  1. 1. College of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
    2. Nanjing Geological Survey Center, China Geological Survey, Nanjing 210016, China
  • Received:2020-04-15 Revised:2020-08-18 Online:2021-09-25 Published:2021-10-29
  • Contact: QIAN Jiazhong

Abstract:

Long-term coal mining in the Suzhou mining area not only led to the formation of shallow groundwater drop funnel but also caused groundwater pollution to varying degrees. In this study, in order to find out the current situation and main causes of pollution, 13 pollution indicators such as NO 3 -were analyzed for 21 groundwater samples obtained from the water and soil pollution survey in the study area. Based on the quality evaluation by the improved Nemero pollution index method, factor analysis and IDW interpolation method were used to analyze the pollution source and its groundwater spatial distribution characteristics. The results show: (1) The shallow groundwater water in the whole study area was heavily polluted to mainly Class IV water and the main pollution indicators were NO 3 -, Mn, Fe and F-. (2) Polluted shallow groundwater were mainly from 4 pollution sources. The first one is the origin’s geological environment (F1), with the high-value areas distributed in the Taoyuan coal mines and surrounding areas. The second one is mining wastewater formed by mine-pit drainage and leaching of Gangue Hill (F2), which caused serious pollution in the Taoyuan and Qianyingzi coal mines as well as some pollutions in other mining areas. The third pollution source is rural sewage (F3) caused by domestic waste and human and animal excreta, which mainly contaminated the areas of Zhuxianzhuang and Luling coal mines. The fourth pollution source is agricultural pollution (F4) caused by fertilizer application, with the high-value areas concentrated in the Zhuxianzhuang coal mine and surrounding areas. The main factors affecting the shallow groundwater quality in the study area were the primary geological environment of shallow groundwater and mining wastewater. About 51.04% of pollution were from a mix of the two sources, about 11.84% from coal mining wastewater alone, and the rest mainly from rural living and production sewage and agricultural non-point source. (3) The major polluted areas were Taoyuan and Qianyingzi coal mines while the pollution in Qinan and Qidong coal mines was relatively light, and the water quality in the Zhuxianzhuang and Luling coal mines was better. (4) It is suggested to comprehensively control the main sources of groundwater pollution by strengthening supervision and control of mine drainage outlet discharge up to the standard. Also coal mining enterprises can improve the overall utilization of gangue by means of making building materials, etc. Furthermore, construction of infrastructures such as sewage and landfill treatment facilities in mining areas should be strengthened.

Key words: Suzhou mining area, shallow groundwater, factor analysis, pollution source apportionment, pollution evaluation

CLC Number: