A Study On The Disposal Of Municipal Sewage By Biological Fluidized Bed Filled With Bamboo Charcoal

In this study, biological fluidized bed filled with bamboo charcoal was applied todispose simulative sanitary sewage. The experiment mainly detected the effects ofcontrolling volume loading, hydraulic retention time and packing particle size on theremoving of COD, ammonia nitrogen, total nitrogen and total phosphorus. And theresults showed that:(1)It was feasible that the experiment applied the continuously feeding water inaccordance with contrivable loading to filling reactor, which was favorable to thestarting of biofilm culturing. In the process of membrane forming, removing rate ofCOD maintained about60%.(2)The system adopted bamboo charcoal as the carriers of biological fluidizedbeds, and its optimal operational condition was water temperature at18℃, gas-waterration at86:1, hydraulic retention time3hours, carriers’ size at10-20mesh, theconcentration of sewage water at100mg/L.(3)The pollutants degradation rates reduced with the improving of volumeloading and increased with the extension of hydraulic retention time and the decresionof the carriers’ size.(4)This system was good at removing COD and total phosphorus and their bestefficiency could reach up to81.4%and64.9%, respectively. However, the totalnitrogen and ammonia nitrogen removal rate was lower than the formers. The systemholds certain impact resistance to the sudden change of the feed water and volatility ofthe four testing indexes were not significant.(5)Filling rate had a great influence on the treating performance. Filling rateshould not affect nitrification and phosphorus removal not inhibit the growth ofmicroorganism. Too much or too less stuffing carriers could directly impact theprocess performance.(6)The state of fluidized carriers directly influenced the treatment effect. Itconcerned not only with the aeration rate, but also with the filler particle size.Through the experimental data analysis, it was known that the smaller particle size,the greater aeration rate, the more sufficient state of fluidized carriers, the better effectof sewage treatment could be gotten. But if there was too much oxygen in the system,it would weaken nitration denitrification effect, cause high energy consumption and increase running cost of this process.(7)Considering the weak denitrification performance of the reactor, theinvestigator found a method that biological fluidized bed was followed by the A/Oprocess. Data analysis showed that biological fluidized bed coupled A/O process couldgreatly strengthen the removal organic efficiency and denitrification performance ofbiological fluidized bed. The removal rate of COD, ammonia nitrogen, total nitrogenand total phosphorus could be up to90.3%,74.2%,77.5%and82.5%, respectively.