Exploration of Hydrogeochemical Characterization and Assessment of Organic Pollution Characteristics of Shallow Groundwater near a Chemical Plant That Discharged Sewage Illegally

Abstract

Groundwater plays a significant role in domestic use and agricultural irrigation in rural areas of northern China. The untreated wastewater from the chemical plant was directly discharged into a seepage well, resulting in the pollution of groundwater. Assessing characteristics of groundwater organic pollution and identifying evolutionary mechanisms of hydrogeochemistry are beneficial for groundwater protection and sustainable management. Statistical methods (correlation analysis (CA) and principal component analysis (PCA)) combined with hydrogeochemical methods including Piper, Gibbs, Gaillardet, and ions binary diagrams and the chloride alkalinity index were employed to explore hydrogeochemical characteristics and evolutionary mechanisms. The results showed that cations were predominantly located at the Ca2+ end and anions were mostly close to the SO42− and Cl− end. The ion concentrations of groundwater were mainly affected by water–rock interactions. The weathering or dissolution of silicate (i.e., aluminosilicate minerals), evaporite (i.e., halite and gypsum), carbonate minerals (i.e., calcite and dolomite), cation exchange, and anthropogenic activities contribute to the chemical compositions of groundwater. Based on CA and PCA, the dissolution of halide minerals and the use of pesticides and fertilizers were the main factors controlling water chemistry. Additionally, the dissolution of sulfur-bearing minerals and gypsum was the key factor controlling the concentrations of Ca2+ and Mg2+. Application of mathematical statistical methods characterized that the exceedance rate of seven organic compounds with high detection rates were as follows: carbon tetrachloride (39.83%) > 1,1,2-trichloroethane (28.81%) > chloroform (10.17%) > trichloroethene (6.78%) > 1,1,2,2-tetrachloroethane (5.93%) > perchloroethylene (5.08%) > trichlorofluoromethane (0.85%). Simultaneously, pollution under the influence of volatilization and diffusion was significantly less than that in the direction of groundwater runoff.

A data-driven quantitative model for predicting floor groundwater inrush risk under deep and thick coal seam mining

“…However, the complex hydrogeological conditions in the deep part of coal mines have led to an increasing risk of water inrush from the coal seam floor, and flooding accidents have also risen year by year (Wu et al, 2011;Wu et al, 2019;Wu et al, 2008;Zhao et al, 2023). There are various factors affecting water inrush from the coal seam floor, and the mechanism and types of water inrush are diverse, which has become one of the major challenges that affect and restrict coal safety production (Gu et al, 2020;Zhan et al, 2022;Zhang et al, 2021). Therefore, it is necessary to accurately predict the risk of water inrush from the coal seam floor.…”

Carbon Quantum Dots Bridged TiO2/CdIn2S4 toward Photocatalytic Upgrading of Polycyclic Aromatic Hydrocarbons to Benzaldehyde

“…In fossil industrial societies, environmental pollution is closely related to the rapid progress of modern industry [ 1 , 2 , 3 ]. Among the kinds of pollutants, more and more public attention has been paid to the ecological environment change caused by organic pollutants [ 4 , 5 ]. In domestic sewage, organic pollutants usually include benzene compounds (Polychlorinated biphenyls) [ 6 ], formaldehyde [ 7 ], tobacco tar (PAHs) [ 8 ].…”