To study the disparity of river hydrochemical characteristics and water quality in different regions of the city, this paper took the Tuo River in the center of Suzhou, Northern Anhui, China and the Bian River on the edge of the urban area as the research objects, used Piper trigram, Gibbs diagram, and hydrogen and oxygen isotope content characteristics to analyze the geochemical characteristics of surface water in the study area, and then the improved fuzzy comprehensive evaluation method was used to evaluate the water quality. The results showed that the hydrochemical types of the two rivers were SO₄-Cl-Na type, and the contents of Na⁺, K⁺, SO₄²⁻, Cl⁻, Ca²⁺, total phosphorus (TP) in the Bian River at the edge of the city were much higher than those in the Tuo River at the center of the city (ANOVA, p < 0.001). Gibbs diagram showed that the ion composition of the two rivers was mainly affected by rock weathering. The results of correlation analysis and water quality evaluation showed that Bian River was greatly affected by agricultural non-point source pollution, and its water quality was poor, class IV and class V water account for 95%, while, for Tuo River, due to the strong artificial protection, class II and class III accounted for 40.74% and 59.26%, respectively, and the overall water quality was better than that of Bian River. The evaluation results of irrigation water quality showed that the samples from Tuo River were high in salt and low in alkali, which could be used for irrigation when the soil leaching conditions were good, while Bian River water samples were high in salt and medium in alkali, which was suitable for irrigation of plants with strong salt tolerance.

The aim of this study is to evaluate the hydrogeochemical characteristics and water environmental quality of shallow groundwater in the Suxian mining area of Huaibei coalfield, China. The natural formation process of shallow groundwater in Suxian is explored using Piper trilinear charts and Gibbs diagrams, and by examining the ratios between the major ions. United States Salinity Laboratory (USSL) charts, Wilcox diagrams, and the water quality index (WQI) are further employed to quantify the differences in water quality. The results reveal that the main hydrochemical facies of groundwater are HCO₃–Ca, and that silicate dissolution is the main factor controlling the ion content in shallow groundwater. The USSL charts and Wilcox diagrams show that most of the water samples would be acceptable for use in irrigation systems. The WQI results for each water sample are compared and analyzed, and the quality of groundwater samples around collapse ponds is found to be relatively poor.

The Taiyuan formation limestone water in the Huaibei coalfield is not only the water source for coal mining, but also the water source for industry and agriculture in mining areas. Its hydrogeochemical characteristics and water quality are generally concerning. In this paper, conventional ion tests were carried out on the Taiyuan formation limestone water of 16 coal mines in the Sunan and Linhuan mining areas of the Huaibei coalfield. Piper trigram, Gibbs diagram and an ion scale coefficient map were used to analyze the hydrogeochemical characteristics of the Taiyuan formation limestone water. The water quality was evaluated in a fuzzy comprehensive manner. The results show that the main cation and anion contents in the Taiyuan formation limestone water were Na⁺ > Mg²⁺ > Ca²⁺ > K⁺, SO₄²⁻ > HCO₃⁻ > Cl⁻. There were differences in the hydrogeochemical types of the Taiyuan formation limestone water in the two mining areas; HCO₃-Na type water was dominant in the Sunan mining area and SO₄·Cl-Na type water was dominant in the Linhuan mining area. The chemical composition of the Taiyuan formation limestone water is mainly affected by the weathering of the rock and is related to the dissolution of the evaporated salt and the weathering of the silicate. The fuzzy comprehensive evaluation results show that the V-type water accounts for a large proportion of the Taiyuan formation limestone water in the study area and the water quality is poor. This study provides a basis for the development and utilization of the Taiyuan formation limestone water and water environmental protection in the future.

This study analyzed the content characteristics, ecological risks, vertical migration characteristics and sources of soil heavy metals (Cr, Ni, Cu, Zn, As, Cd and Pb) in affected areas of Luning Coal Mine. Results showed that the average contents of Cr, Pb, Cu, As and Cd exceeded the surface soil background values of Anhui Province, but the risk of soil ecological environment was low. Cd had the largest single factor pollution index, As followed, and Cd in 14 sampling points reached the warning limit, 95% of the samples were in moderate hazard, 5% of the samples were in strong hazard, but the potential ecological hazard index of many kind of heavy metals was 81.81~121.41, which was low ecological hazard. The difficulty of vertical migration of heavy metals in soil was from easy to difficult: Cr>Ni&Cu>As>Zn>Cd&Pb; Cu, Zn and Pb were related to automobile exhaust emissions and transportation dust, Cd and Ni were mainly caused by natural geological processes, leaching of coal gangue hill and the discharge of industrial pollutants, As was mainly caused by agricultural activities, and Cr was closely related to coal combustion.