Trials And Studies On The Biological Aerated Filter With Pre-denitrification For Municipal Wastewater Treatment

Nowadays waterhsortage and water pollution are two serious prolems faced by water resources and treatment capital is relative lack.Therefore,it is necessary to find a new sewage treatment technology adapting the situation of China with low capital construction investlment,low runing cost ,convenient management and preferable treatment efect.BAF is the right choice with characteristic of facility,good effect and low consumption. Biological Aerated Filter is a new wastewater treatment technology which is draw water filter technology development in general based on biological filter.BAF use particle filter. It has retained suspended solids and biological treatment combined with functional features. It also has filtering, adsorption, biodegradation and other functions. Engineering practice shows that it has a small footprint, high treatment efficiency, shock resistant capability, without the secondary settling tank, and good water quality. The trial is treating wastewater by denitrification BAF. We have studied the denitrification biological aerated filter process on the organic matter, nitrogen removal to explore the removal law of pollutants for obtaining the optimum working parameters. The trial provide theoretical basis for the denitrification process to promote biological aerated filter to for the field of sewage treatment in our country.The results show that denitrification BAF has a good performance purification of domestic sewage. Hydraulic loading of 1.91m / h and reflux ratio of 200% is the optimal condition. Effluent COD and ammonia nitrogen were respectively 34.71mg / L and 3.33 mg / L. It is meet the quality standards of the city back water. We investigated the hydraulic loading, water temperature and filter height of reactor through the experiment. The experimental results show the optimal conditions of this experiment is the hydraulic loading reactor 1.91m / h and reflux ratio of 200% .Biological Aerated Filter system has an effective backwash by way of jointing air and water. The concentration of effluent COD recover to normal levels during 5 to 6 hours after an anti-flushing. Turbidity levels can returned to normal levels in 3 to 4 hours. Biological Aerated Filter removal of NH4+-N is less affected by backwash process.