| Shortage of water resource is an important restricting-factor of the economy and society development in China,and a great deal of municipal sewage directly draining into water body without any treatment or with little treatment is a main cause why the quality of water environment has been deteriorating as a whole. So it is urgent to research and develop simple,high-efficient,low-consumptive treatment techniques for municipal sewage correspond to the situation of China. Aerated biofilter is one of the important technical approaches to resolve the problem. The study focuses on municipal sewage treatment using an aerated biofilter in which enzyme-promoted media is used. It includes start-up of the filter under condition of natural temperature,and performance of the filter treating municipal sewage under some hydraulic retention time(HRT), and the effects of the parameters correlated to the filter.The results demonstrate:It takes about 14d to complete the start-up under the condition of 22.1～27.8℃ with the sludge of gravity thicken tank as seed. When the COD in influent varies between300～500mg/l,and HRT is 8h,the ratio of air flow rate to wastewater flow rate is 7,the effluent can reach first standard B species of GB18918-2002. Besides, N,P in influent can be remove to some degree. The results also indicate that the height of media layer affect the removal of organic substrate and suspended solid; the up-flow BAF is better than down-flow BAF in treating municipal sewage.At the same time, dynamic model of the aerated biofilter treating municipal sewage is deduced according to the experimental date. The model is: (g/(m2.d))Based on the model,effluent quality could be forecasted. |
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