Experimental Study On Biological Aerated Filter Deal With Micro-polluted Source Water

At present, worldwide drinking water is polluted. Conventional treatment is not very efficient in the removal of organic pollutants from source water and chlorination process causes the formation of organic halogen, which is more dangerous to health. Consequently, the researches of effective, practical and economical methods are of great importance and realistic meanings. Biological water treatment is an economical and effective water treatment method with toxicology safety. Biological treatment procedures has shown potential application with the characteristics of small size, higher load capacity, hydraulic retention time, less investment, high water purification process quality, etc.With the laboratory simulation test of slight-polluted sources water, different fillers: ceramisites, zeolites, zeolites-The removal efficiency of start-up of biological cotton filling combination BAF is analyzed. The experimental results show that the removal efficiency of ammonia nitrogen and organics and turbidity by double packing BAF reach32%and92%and85%respectively, which is the best in the condition of hydraulic retention time1h, DO6mg/L, temperature16～24℃,ph7.0～7.5.The influences, including hydraulic loading, air-water ratio, temperature, shock loading, ph, anti-eroded, filter closing are deeply researched based on the pollutants removal efficiency of double packing BAF. The results reveal that the optimal operate parameters are hydraulic loading3m3/m2-h, air-water ratio1:1, temperature20～30℃, pH7～7.5. Filters have a strong ability to against ammonia nitrogen and manganese loading, and can be maintained higher removal efficiency under the optimal operational conditions. But ammonia nitrogen removal rate is decreased, when the organic concentration of influent water at or above14mg/L. This experiment carries through filter backwashing water by adopting technique of air and water combination backwashing. After backwashing of4h, filters restore removal efficiency of ammonia nitrogen and organics. According to the pollution, backwashing can last15～30days. Restart-up after closing for22days, filters restore the removal efficiency of organics in8h, has little influence on ammonia nitrogen.