Study On The Drinking Water Treatment Scheme Of Compound Micro-polluted Groundwater Sources

Groundwater is an important drinking water source of our country. Because of pollution infiltration, over-exploitation and some other reasons, the quality of groundwater is worse year by year. In the past, the overproof items include iron and manganese, at present, the polluted water source translates into compound micro-polluted groundwater. The original treatment process can't adapt to the deteriorative water quality, the problem of compound micro-polluted groundwater should be resolved as soon as possible.For experimental investigation, this paper adopts two routine water treatment technologypotassium permanganate oxidation-filtration and aerating-contact oxidation method to deal with the micro-polluted groundwater. The same parameters are used in the filter process, by the analysis of the treatment effect, the feasible processing method is optimized,and we find out a method that can be used in the engineering practice.We study the treatment effect of oxidation-filtration and aerating-contact oxidation method when the filter column and filtering velocity is identical.Dosing quantity of potassium permanganate is 16.8 mg/L,and the oxidation time is 15 min.When the filtering velocity is lm/h, the mean concentration of iron, manganese?ammonia nitrogen and organic matter after oxidation-filtration is 0.130 mg/L?0.163 mg/L?2.657 mg/L?0.024 mg/L, and the mean concentration of iron?manganese?ammonia nitrogen and organic matter after aerating-contact oxidation is 0.109 mg/L?0.062 mg/L?0.134 mg/L?2.781 mg/L.The water's content of iron?manganese and organic matter after oxidation-filtration can reach the standard of (Standard for Drinking Water Quality)) (GB5749-2006), but the content of ammonia nitrogen can't reach the standard.All the indicators of the water after aerating-contact oxidation can reach the standard. The highest filtering velocity is 4 m/h,the mean concentration of iron, manganese, ammonia nitrogen and organic matter after oxidation-filtration is 0.121 mg/L?0.034 mg/L?0.434 mg/L?2.170 mg/L. Aerating- contact oxidation does better than oxidation-filtration in dealing with this kind of water.By the comparison test of oxidation-filtration, oxidation absorption combination and aerating-contact oxidation, feasibility research and analysis, the aerating-contact oxidation method is optimized as the best method to deal with the micro-polluted groundwater.The technological process is:spray aerating-first filtration-drop aerating-secondary filtration-chlorine dioxide disinfection.The project is aimed at the water quality of Liguanbao waterworks, the contrivable yield of water is 50000 t/d. On the basis of small test results wo got and the relevant test results, we analyze and confirm the main structure and parameters.The specific parameter is as follows:two sets of the same structure are parallel running,each set is consisted of two series of ordinary filter, ceramics are the filter material, the height of filter material in each filter chamber is 1m, the filtering velocity is 2 m/h, the back washing intensity is 12 L/(m2·s), the back washing time is 5?10 min, the back washing cycle is 2d. Chlorine dioxide is choosed as the disinfector. The Direct operating cost(maintenance cost of equipment. depreciation cost and cost of labor is taken out) is 0.051 yuan/m3.