Study On The Influence Of Typical Ion On The Changes Of Total Hardness Of Groundwater

Through the Beijing area of hydrogeology survey, Analysesing the factors that affect groundwater hardness increases. Papers to the faubourgs of Beijing typical different soil vadose zone as the research object. Under the condition of indoor, with different concentrations of NaCl, NH4Cl and different pH value on behalf of the typical Na+, NH4+,H+ ions to dissolve test of soil.Calculate total hardness of the leach liquor relationship with soaking solution concentration and oscillation time. Through using thermodynamic curve fitting of the variation of total hardness of leaching solution with immersion liquid concentration, the rule of the hardness of soil replacement are obtained; through using dynamic model on the total hardness leaching solution changes with the leaching time, gets the regular of total hardness replacement of soil with leaching time.The results showed that:NaCl, NH4Cl solution and acid solution will produce certain effect on groundwater hardness. The effection of NH4Cl solution has a maximum intensity. The displacement law curve of three layers soil total hardness are almost the same in the same solution, are all increase with the increased concentration. After reaching the maximum, then will no longer continue changing. In the early, dynamic curve is steep. After 1h exchange rate gradually slow down, Kinetic curves flatten out, Replacement nearly reach the equilibrium. The kinetic curve with five dynamics model fitting, the results show that:In line with the double constant model in sodium chloride solution and acid solution, Elovich model, first order kinetics model; in ammonium chloride solution meets the secondary dynamic model.Through above analysis of the main factors influencing the groundwater total hardness increases, provide the basis for prevention and control of groundwater hardness increases.