Biofilm Synchronization Effect Of Nitrification And Denitrification

As the water eutrophication becoming more and more serious, especially as the standards of nitrogen and phosphorus had been improved, It is necessary to develop a high-efficient, low energy required and simply operated technology to nutrient removal.In this paper, the biological contact oxidation reactor(its main dimensions are: Diameter is 10cm, Height is 80cm, Effective Heigh is 75cm, Volume is 6.3 L, Working Volume is 5.8 L ) is made of synthetic glass. And the biological filler is tridimensional elastic packing. The raw wastewater is low concentration domestic sewage, which is taken from the water treatment plant of Kunming University of science and technology BaiLong compus. The regular that the main factors such as water temperature, HRT, pH, DO, and COD concentration (or C/N ratio) affected SND had been researched; According to the regular of COD, Ammonian, NO_x~- - N, TN and TP transformed in the reactor, the mechanism of the SND was also studied; Further more, through the relation between the removal rate of COD,Ammonian,TN and the HRT , the Kinetical Equation of COD degradation, nitrification and denitrification were established; Finally, prospect of the biofilm process in the wastewater treatment was Analyzed. The main conclusions are:1, The optimum condition for SND are: HRT is 10h; water temperature is above 15℃; pH is 7.5; DO concentration is 2.5 mg/L; COD concentration is about 400 mg/L. At this condition,the TN, TP removal rate could reach about 70% and 40% respectively.2, Based on the previous relevant research work , it is appropriate that using the Microscopic Environmental view and the Microorganism Theory to explain the mechanism of the SND in biofilm process: at the condition of low DO concentration, because of the DO concentration gradient which exists in biofilm, the biofilm could classify three party from outside to inside: layer of oxygen, layer of oxygen deficient, anaerobic layer. First, the surface of biofilm which have large adsorption capacity adsorbs the organisim and other nutrient substance(e.g. N, P); Then, because the oute(?) layer of the biofilm(about 1~2 mm) is layer of oxygen which is consist of some aerobic bacteria such as nitrifying bacteria, the nitrification and the part of COD degradation...