The Key Technology Research Of Continuous Flow Biofilm Partial Nitrification

With the development of socio-economic and the improvement of people’s livingstandards in China, the nitrogenous organics in wastewater increased rapidly, thewater environment deteriorated sharply and increasingly serious problem ofeutrophication, so effectively decreased nitrogen pollution in the water becomes veryimportant. But the traditional process is difficult to achieve efficient ammonia，theneed to develop new biological nitrogen removal technology nitrogen removal. Partialnitrification technology has been studied widely because of its advantages such as lowcoast, good effect and low energy consumption, and the application of Biofilmprocess has more and more widely in the sewage treatment process, because of itsadvantages compared to the activated sludge method.In order to achieve partial nitrification of continuous flow biofilm, in thisexperiment, it transformed sequencing batch biofilm reactor (SBBR) into a continuousflow for the test device, treated synthetic domestic wastewater as the research object,and used the combination of fiber filller as biofilm carrier. It investigated andanalysised of continuous flow biofilm hanging film start and run processing, focusingon different control conditions (such as HRT, DO, the pH, the C/N ratio, etc.) underthe realization of the influence of nitrous accumulation, determined to achieve partialnitrification optimum operating conditions. in the final,it also analysised ammonianitrogen removal and partial nitrification under high ammonia nitrogen. Experimentalresults indicated that:(1) Dissolved oxygen (DO) is a key factor affecting partial nitrification ofcontinuous flow biofilm system. When NH4+-N concentration in the influent of60~65mg/L, HRT=6h, DO=4.5mg/L, the system mean the concentration of the effluentNO2--N average and the accumulation rate was17.26mg/L and52.68%，and achievethe initial accumulation of NO2—N.(2) Accumulated by the system partial nitrification control conditions study found HRT, pH value, C/N ratio has a certain influence. Under best operatingconditions, DO=2.0mg/L, pH=8.0, C/N=1.0, HRT=6h（Influent NH4+-Nconcentration of60~65mg/L）, the effluent nitrite nitrogen is very stable, theconcentration of the effluent NO2--N average was up to34.48mg/L, the accumulationrate was up to90.10%, the entire effluent NH4+-N control below5mg/L, Reached ahigh level of nitrosated, had been achieved partial nitrification of continuous flowbiofilm.(3) The high ammonia influent (120-130mg/L), extension of the hydraulicretention time (HRT) not only contribute to the removal of ammonia, but also tomaintain a good accumulation of nitrous. When DO=4.5mg/L, pH=7.5, HRT=10h, C/N=1.0, the average concentration and accumulation rate of effluent NO2—Nare48.15mg/L and78.60%, respectively, to achieve partial nitrification under highammonia water.