Hydrogeochemical Processes and Connection of Multi-Layer Groundwater System in Sunan Mining Area, Eastern China

Abstract

Groundwater is an important freshwater resource in the world and serves as the main source of water for mining areas in Northern China. Coal mining may cause changes in water quality. As such, to identify ways to prevent water contamination, this study investigates the hydrogeochemical processes and transport paths of a complex aquifer system in the Sunan mining area in Northern China. Using the APFS-MLR model, a geographic information system (GIS) spatial analysis, and a hydrochemical correlation analysis method, this study identifies the potential mineral phases in groundwater, the spatial distribution of mineral reactions, and the contribution rate of these reactions to hydrochemical variables. Inverse modeling is used to verify hydrogeochemical process. The study reveals the relationship between multiple aquifers and four hydrological transport paths. Here, Path 1 and Path 2 show that the Quaternary aquifer, Carboniferous aquifer, and Ordovician aquifer are recharging the Permian aquifer through mineral dissolution and precipitation, cation exchange, and sulfate reduction. On the other hand, Path 3 and Path 4 show that tthe connections of Carboniferous and Ordovician limestone aquifers are dominated by the dissolution and precipitation of minerals and cation exchange, and that they are mainly recharged by the Quaternary aquifer. In the future, the water level of the Permian aquifer may rise somewhat after mining ends, and the mixing of water from the Permian aquifer, Quaternary aquifer, Carboniferous aquifer, and Ordovician aquifer could cause cross-pollution. In addition, sewage produced by human activities may recharge the deep water through the shallow water, polluting the deep karst water. As such, measures should be taken to reduce the hydraulic connection between Permian mine water and karst aquifers. The results of this study may benefit water quality predictions and treatment approaches in other complex multi-layer aquifer areas in the world.

Estimation of Polycyclic Aromatic Hydrocarbons in Groundwater from Campania Plain: Spatial Distribution, Source Attribution and Health Cancer Risk Evaluation

“…The coordination system from the Global Positioning Satellite (GPS) receiver was utilized to fit the actual map. For the distribution map, ArcGIS software was employed, and the concentration of PAH was displayed on the GIS map throughout the Campania Plain [ 46 , 47 , 48 ]. Figure 3 shows that the distribution characteristics of PAH content in the groundwater of the CP are significantly different.…”

Deep Groundwater Flow Patterns Induced by Mine Water Injection Activity

“…Groundwater is an important part of the global hydrologic cycle [ 1 ]; it is growing in demand in arid and semi-arid regions, especially in China. Mine water drainage [ 2 ] from coal mining areas, such as the Ordos Basin, Tarim Basin and Junggar Basin, aggravates this situation. Meanwhile, mine water is considered as one of the non-traditional groundwater resources, which is especially important during extreme events.…”

Spatial and Temporal Evolutions of Shallow Groundwater with Anthropogenic Activities: A Case Study of Sunan Mine Region, China

“…The shallow groundwater in the Sunan mining area is seriously affected by mining, and according to the Groundwater Quality Standard, about 90% of the groundwater is Class IV water, which does not meet the standard for residential use [25]. In this paper, we analyze the groundwater quality characteristics of different periods, use cluster analysis and principal component analysis to study the sources of groundwater components and their mechanisms of action in different periods, and use the inverse distance weight (IDW) interpolation method to study the spatial and temporal evolutionary characteristics of groundwater genesis.…”