Assessment Of Water Environment Quality And Prediction Of Environmental Capacity In Kubai And Hami Mining Areas

With the high intensity mining of coal,the water environment quality is worsening,disrupting the water ecological balance mechanism,and the water environment capacity in coal mining areas is facing enormous pressure.At the same time,under the influence of mine sewage,the content of heavy metals in the soil changes accordingly,and the structural distribution is severely damaged,resulting in a continuous decline in soil quality.Based on the above content,this study focuses on several important mining areas in Kubai and Hami,Xinjiang.This study is to evaluate the water quality of each water body using single factor and principal component analysis methods,to study the characteristics of pollutant changes and water quality status;based on multiple water quality models such as MIKE11,analyze and calculate the water environmental capacity of the coal mining area river section;the evaluation of the impact of heavy metal pollution in soil under the influence of mine water was carried out using the methods of ground accumulation index and nemero index,revealing its variation distribution pattern.The main research results of this article are as follows:（1）In the study area,the main pollution factors of domestic sewage are SS,BOD₅,and COD,and the treatment effect is good;after analysis and evaluation,the pollution level of SS in water is the highest,and there is no significant correlation between the main pollutants.（2）In the study area,the main factors that exceed the standard for mine water include SS,COD,total hardness,and TDS,which meet the standards for reuse of miscellaneous water after treatment.After evaluation,the water quality is greatly affected by SS and COD;and the ions in the water are mainly Na⁺,Cl^-,and SO₄^2-,and the hydrochemical type is mainly Na·Ca-Cl·SO₄ type,which is a typical high hardness,high mineralization,and high salt water.（3）In the study area,the groundwater generally exhibits weak alkalinity and high salinity,with high total hardness and mineralization.Some water bodies are relatively severely polluted by organic matter;the hydrochemical type is mainly Na·Ca-SO₄·Cl type,and the ions have significant correlation,mostly from the dissolution of carbonate,silicate and evaporite;moreover,there are certain differences in the study of water quality changes and distribution characteristics in mining areas.（4）There was no excessive acidification or alkalization of the soil in the study area;moreover,the soil in the mining area under the influence of mine water is generally within the warning range,with some soils experiencing mild pollution,and a few at moderate or severe pollution levels.（5）The COD water environmental capacity of the Weigan River section in the coal mining area is 800.99～4272.81 g/s,the ammonia nitrogen water environmental capacity is 39.56～231.95 g/s,and the TN water environmental capacity is-154.02～30.61 g/s.The water environmental capacity is relatively stable during the dry season and changes significantly during the wet season.The river has obvious characteristics of water environmental capacity changes.