Study On Simultaneous Nitrification And Denitrification Of SBBR

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. As a new biological nitrogen removal, Simultaneous nitrification and denitrification has some advantages, such as high efficiency, simple process, easy operation, low consumption and so on. In the field of water pollution control, particularly in urban area sewage recycling has a wider range of foreground in applications and is up to the requirement of our country.This paper prepared by artificial simulation living sewage was treated to tridimensional elastic filler for biofilm carrier. In the SBBR system the regular that the main factors such as HRT, pH, DO, and COD concentration (or C/N ratio) affected SND had been researched; and the best controlling condition of the factors had been gained. The research had showed that, DO concentration and C/N ratio were the main factors affecting SND nitrogen removal, and the phenomenon was analyzed through biofilm SND phenomenon on the reaction mechanism. The main conclusions are the following:1. Biofilm SBR method has a good effect on the COD removal. It is not obvious for different influent PH, DO concentration, C/N ratio (COD concentration) to affect the COD removal efficiency, and the efficiency was all more than 85%. So it was obvious that biofilm resistance of the organic loading capacity is very strong.2. Through test analysis, the best SND denitrification process parameters were: pH was 7.5 (better SND results can be got among 7.0-8.5 in the PH); DO concentration was 2.5mg/L; influent COD concentration was 500 mg/L, TCOD/TN ratio was 11 (but better effect SND nitrogen can be got when TCOD/TN ratio was 9 to 13, because TCOD/TN appropriate scope was wider).3. In the best parameters condition drawn by the test, a cycling experimental had been operated. when influent NH₄⁺-N and COD concentration was 500 mg/L and 45 mg/L, the removal rate could reach about 93% and 84% respectively, and the effluent were below the B grade of first grade discharge standard of GB18918-2002, testing the best factors reliability. Contrasting the cycling operation of SBR and SBBR-SND technology, the superiority SBBR system was proved.