Performance Comparetion On The BAFs With Different Carriers To Treat Municipal Wastewater

The project which is the coopration of the School of Environmental Science and Engineering (ESE) of Huazhong University of Science and Technology (HUST) and Wuhan Xintiandamei Environmental Technology Limited Liability Company (WXET L.T.D), is aimed to invent a new technology which is on the basis of"the depth of purification and sewage treatment technology of STCC"which is owned by WXET L.T.D. This technology should have better performances, eg: anti-loading performance, simple structures and easy maintenance. So three Biological Aerated Filters (BAFs) with different carriers (STCC, charcoal, ceramic) to treatment municipal sewage are studied. This article studied on the start-up process, the influence factors and the space character of the STCC, charcoal and ceramic BAF to provide a basis for further experiments. The results indicated:It takes about 25 days for the STCC, charcoal and ceramic BAF using the method of continuous flow seeding with activated sludge to start-up. The best hydraulic loading of the three BAFs is 0.070-0.093 m3/ (m2?h). The best DO of STCC and charcoal BAF is 2.5-4.0 mg/L. An increase of the hydraulic loading impacted COD, SS of the effluent little, but reduced the NH3-N and TN removal of the three BAFs. And the ceramic BAF is affected more greatly.The DO influence the removal of the three BAFs greatly. When the DO belows 1.5 mg/L, the effluent COD, SS, NH3-N, TN of three BAF are not standard. When the DO is higher than 1.5 mg/L, the COD and SS of the three BAFs can be standard. But the NH3-N can't. Then improving DO does little to the COD removal. When the DO is higher than 2.5 mg/L, the NH3-N of the STCC and charcoal BAFs can be standard. Then improving DO does little to removal of NH3-N. When the DO is higher than 4.0 mg/L, improving DO inhibit to the TN removal.Study on the STCC BAF shows: The organic matter and NH3-N removal reduce gradually on the filter bed with the height increases. The removal of NH3-N is lower than the removal of COD along the fluent direction. When the hydraulic loading is increased or the temperature falls, the carrier on the bottom of the filter does more contribute to the removal of COD.Study on the charcoal BAF shows: Different forms of nitrogen on the different height of filter beds are different. The removals of NH3-N and TN increase with height of the filter bed increased. The consistence of NO2--N increases gradually. The consistence of NO3--N increases at first, and then gradually reduced with the effects of denitrification. The removal of NH3-N dynamic equation of charcoal BAF for this experiment is C N = C N0 e?Kh, the value of K is 6.8281.In general, the charcoal BAF is better than STCC BAF which is better than ceramic BAF under the same control.