The Research Of Ceramic-slag Double-layer Medium Biological Aerated Filter For Pretreatment Of Sewage

BAF treatment of urban sewage is favorable. It is simple in structure, easy operation, low operating costs. After nearly 10 years developing rapidly, technology matures. BAF will become one of the main solutions which is the most important way to solve the serious water pollution and water shortage means. The paper focus on the treatment effect which Ceramic - slag double filler BAF treatment of domestic sewage treatment. Experiments show the effect of the treatment process. And to study the temperature, gas-water ratio, HRT on Biological Aerated Filter for performance.Ceramic - slag double filler BAF used in the natural membrane, for a relatively short time, 24 days after the successful film hanging. COD and ammonia nitrogen removal rate were stable at 75%, 60%. Long-run results show: Filter for COD, ammonia and other SS has good removal efficiency, the average removal rate reached 83.5%, 69% and 90% respectively. Ceramic - slag double filler BAF performance of the major influencing factors: temperature, gas-water ratio, HRT. Gas-water ratio of COD and ammonia nitrogen greater impact, gas water ratio 2:1, Filters can achieve carbon oxidation and nitrification at the same time handle. To the HRT , the gas-water ratio of 2:1, HRT 6h ～24h between changes Reactor to 1:15 unaffected, but the removal of ammonia greater impact, with the increased HRT ammonia removal is significantly increasing.Backwash is one of the main factors that affected Ceramic - slag double filler BAF processing performance. Through the filter backwashing, the backwash strength and backwash cycle of research, the results showed: filter backwash cycles and the head loss through the water to determine water quality. HRT of backwashing cycle of larger, with the HRT increase backwashing cycle increases. Backwash the following manner: First, gas cleaning and then air-water backwashing joint, the final rinsing water. It made a good backwash effect. Backwash parameters: Backwash gas 5L(m~2·s), washing lasted 5 minutes, air-water backwashing joint, the backwash water 2L(m~2·s), volume remained unchanged, Backwash lasted 5 minutes, the intensity of water rinsing 2L(m~2·s), 15min sustained time.