Study On The Reclamation And Reuse Of The Municipal Wastewater By The Biological Sand Filter

O / A biological sand filter is a filter on the basis of the traditional rapid filter, full access to draw on the design ideas of contact oxidation method and biological aerated filter, that the set formed by aeration, physical retention, biodegradation, high filtration rate and so on in one of the new wastewater treatment technology. O / A biological sand filter is essentially a biofilm reactor, processing core is biofilm that attached to quartz sand, therefore the oxygenation effect of the reactor, hanging membrane properties, the backwashing process operation and control is the key. Studing the characteristics of the hanging biofilm, operating parameters and reactor of the nature of the research Biological sand filtration technology, obtained the following conclusions:Hanging membrane started on March 17 2009, expire on March 17 of 2009, lasting 28 days. During hanging membrane period, the average removal rate of bio-sand filter process to CODCr, NH4+-N, TN waws ;The test found that gas-water ratio has a greater impact on hanging membrane, Early small gas-water is more suitable for hanging membrane needs then the late medium gas-water; during the backwash of hanging membrane, studies have found that a modest counter-washing can promote biofilm growth..In sewage and water conditions, the empty barrels and biological sand filter column aeration and oxygenation properties were studied, found that KLa subjected to water quality, aeration intensity, filter and other factors ,leading into AHP level analytic approach, the water temperature, water quality, water flow state, aeration, filtration and so on, the impact of weight on KLa were 0.2593 , 0.2123 , 0.2123 , 0.1738 , 0.1423 . Analyzing hydrauLic loading, gas-water ratio's influence to sand filtration process for biological decontamination effect, finding that when hydraulic loading is 3.0m / h, gas-water ratio is 3:1, the bio-sand filter column effluent can meet first class A standard of GB18918-2002,it also can get the maximum optimization in energy utilization and water handling.Building orthogonal test and taking sand filter head loss and the removal rate R as the evaluation of anti-flushing conditions. The results show that the head loss is reduced by 24% to 68%,and the head loss is enhanced by 9.4% to 34.9% in biological sand filter after backwashing compared with that before backwashing. The optimal operation parameters are determined as follows: the single air backwashing intensity,single water backwashing intensity,combined backwashing intensity are 12L/m~2·s,10L/m~2·s and 5L/m~2·s respectively,the single backwashing time,single water backwashing time and combined backwash time are 3min,5min and 4min respectively. The air backwashing intensity is the important factor influencing backwashing efficiency of the filter.