Experimental Study On Optimum Municipal Wastewater Treatment In Biological Aerated Filter

In recent years, the countries to strengthen investment in wastewater treatment plant transformation, some wastewater treatment plant effluent does not meet Urban sewage treatment plant emission standards (GB18918-2002)A standard. Under this situation, the development of a good depth of treatment of sewage treatment technology is particularly important. Biological Aerated Filter in recent years, new development of a biological wastewater treatment technology, it can set biodegradable solid-liquid separation in one of the sewage treatment equipment, has a small footprint, no secondary settling tank, good effect, water quality and stability characteristics.Test the effluent of a wastewater treatment plant in Taiyuan, inspected the two biological aerated filter (anoxic and aerobic segment) in the hydraulic retention time, the reflux ratio, gas and water, carbon and nitrogen than the height of the filter Factors affecting removal of the effect the change. The test the stuffy exposure method biofilm stuffy exposure15days after the biofilm anoxic CODcr removal rate reached30percent, the aerobic reactor ammonia removal rate reached80%.The results show that the effect of biological aerated filter depth treatment of municipal sewage:The hydraulic retention time of4hours on the removal of organic matter CODcr, ammonia and total nitrogen are highest, are as follows:77.53%,98.32%,76.416%. Organic CODcr, ammonia nitrogen and total nitrogen removal reflux ratio of1:1for the highest, are as follows:74.75%,94.4%,69.15%.Gas-water ratio of3:1organic CODcr, ammonia and total nitrogen removal rate was the highest, are as follows:80.26%,96.79%,73.10%.C/NH4+-N ratio of10, the organic removal efficiency of CODcr the highest, reaching80.26%; C/NH4+-N ratio6:00of ammonia nitrogen removal rate of96.79%; C/NH4+-N ratio8:00total nitrogen removal is the highest, reaching64.23%.Anoxic or aerobic segment, filter height of50cm CODcr and ammonia nitrogen removal rate of organic matter have been close to their total removal rate.Chemical phosphorus removal, in the same circumstances, the PAC pharmaceutical dosage compared to small and phosphorus removal, the better, the effluent pH values change a little change from6.7to7.2.Biological Aerated Filter to treat municipal sewage backwash cycle set about15d BAF backwash strength as follows:gas loose Time1-3min strength of10～12L/(m2·s); gas-Joint backwash time in less than3min, gas flushing intensity range are7～8L (m2·s), water flushing intensity range are3～4L (m2·s); water rinse time of5～8min, the intensity of～4L/(m2·s).Using a standard A two-stage biological aerated filter depth treatment of municipal sewage make the water quality up to the " Urban sewage treatment plant emission standards (GB18918-2002)A, namely:of CODcr <50mg/L, NH3-N<5mg/L, TN<15mg/L, total phosphorus <0.5mg/L,. And the process is economically reasonable and technically feasible.