Experimental Study On Treatment Of Acidic Pond Wastewater In Rural Ares

The water environment is one of the most important elements in the natural environment.The governance and protection of the water environment is the key link for China's sustainable development.In recent years,the problem of water pollution in pits and ponds in rural water environment has become more and more serious.Pothole ponds that should be used in rural natural ecology have become a serious source of pollution.Some have threatened the surrounding surface water and groundwater and become beautiful.The stubborn disease in rural construction has affected the development of the rural economy and the normal life of the people.The water environment management in the pit pond has become an urgent problem to be solved.This experiment takes the pit pond wastewater in a village in Renqiu City as the research object.It mainly tests and records three pollution indicators of water COD,ammonia nitrogen and total phosphorus,and explores the best processing parameters.The following tests are carried out:First,the water quality of the pit pond wastewater is tested.The p H is 2.3~3,the average COD is 1600 mg/L,the average value of ammonia nitrogen is 213 mg/L,the average value of total phosphorus is 13.0 mg/L,and the suspended matter is 5.5 mg/L.The other four items other than suspended solids cannot meet the Class A standard in the Pollutant Discharge Standard for Urban Sewage Treatment Plants(GB18918-2002).Followed by dynamic testing,the first stage is system sludge cultivation and domestication.Firstly,choose to use the more economical alkaline neutralization reagent calcium hydroxide powder to explore the neutralization of the pit pond wastewater to neutral.After that,the activated sludge was domesticated and cultured by simulated A2 O process.The test records of sludge and effluent COD,ammonia nitrogen and total phosphorus were used as the successful indicators for cultivating domesticated sludge.The second stage is single factor change and orthogonal test.The single factor change test analysis shows that the orthogonal test condition is that the mixing ratio of pit pond wastewater to domestic sewage is 1:11,1:8,1:5;sludge reflux The ratio is 70%,80%,90%;the dissolved oxygen of the aerobic pool is 2~3 mg/L,3~4 mg/L,4~5 mg/L;the hydraulic retention time is 12 h,10 h,8 h.According to the orthogonal test table of L9(34),the orthogonal test of nine parameter combinations is arranged.After running the system,the factors affecting the removal effect of COD can be determined according to the experimental results: mixing ratio>R>DO>HRT;affecting Various factors for the removal effect of NH4+-N: mixing ratio>R>DO>HRT;factors affecting the removal effect of TP:mixing ratio>DO>HRT>R;final determination of optimal operating conditions: mixing ratio 1: 8.The dissolved oxygen in the aerobic tank is 3 mg/L to 4 mg/L,the sludge reflux ratio is 90%,and the hydraulic retention time is 10 h.In the final stage of the test,the system was operated according to the best operating conditions.The effluent COD and ammonia nitrogen concentration reached the first-class A standard in the Pollutant Discharge Standard for Urban Sewage Treatment Plants(GB18918-2002).The total phosphorus could not reach the standard,and PAC,PAM,Fe Cl3 was used as a phosphorus removal reaction agent,and the three agents were prepared into a solution of 20 g/L,1 g/L,and 30 g/L for chemical phosphorus removal test.The best phosphorus removal agent was determined by PAM,and the optimum dosage was 0.70mg/L.