Research On Characteristics Of Two-sect Up-flow Biological Aerated Filter For Municipal Wastewater Treatment

To develop city sewage treatment technology which has low consumption and high efficient is very important for the urbanization in China . Biological aerated filter (BAF) has been widely concerned in recent years in municipal wastewater treatment for its advantages of high treatment efficiency and low landuse .To the mall-and-medium-sized towns in China,BAF has a widely applications prospects . With appearance of the new media, how to optimize the potential of BAF, extend the operating cycle , which directly affects the application and promotion of BAF.In Two-sect UBAF to be achieved functional area, the biological classification, the first sect from the edge of microbial bacteria,mainly removes COD, while the second sect trained autotrophic nitrifiers mainly removes ammoniac nitrogen , thereby Two-sect UBAF has stable, good outflow quality. Group tests using three different medias analysis the start-up performance, result of treating the municipal sewage and backwash characteristic about Two-sect UBAF .During the first phase, enzyme-enhanced anaerobic bio-filling was used. HRT of BAF C is maintained 4h,6h and 8h,while HRT of BAF N is maintained 2.0h,2.5h and 3h respectively,thus,9 groups of experiments are designed by controlling HRT. The results show that Two-sect UBAFcan get ideal and stable removal of COD, ammoniac nitrogen and SS .When HRT of BAF C and BAF N is, 8h and 3h respectively, COD and ammoniac nitrogen values of effluent are in a range of 9~15mg/L and 5.5～7.8mg/L respectively which can meet the requirements of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant ,while COD and ammoniac nitrogen removal rates each 95.7% and 79.1%. When HRT and inflow,s COD of BAF C is 4h and 219~313mg/L respectively, effluent , s COD concentration and removal rate are 50~82mg/L and 70%, it will be able to reduce the organic load of BAF N and meet the condition of nitrification.During the assembled media phase, semi-soft media and enzyme-enhanced aerobiosis bio-filling are used in BAF C and BAF N respectively. HRT of BAF C is maintained 3.6h,4.4h ,5.8h,and 7.2h,while homologous HRT of BAF N is maintained 2.9h,3.6h,4.6h and 5.8h,thus,4 groups of experiments are designed by controlling HRT. The results show that when the total HRT is 8 hours Two-sect UBAF can get best treatment effect .In this condition,BAF C and BAF N can exert their respective...