Study On The Modified ICEAS Process For Simultaneous Nitrification And Denitrification

MICEAS is a denitrification and phosphorus removal system, aiming at low-concentration municipal sewer. The process combines A2/O and ICEAS process, including anaerobic area, anoxic area and aerobic area. During the running of examination, it has get efficiency of simultaneously removing nitrogen and phosphorus and has strong stability. According to the former study and characteristic of MICEAS system, the dissertation carried out a test analysis on the effect under low temperature condition and simultaneous nitrification-denitrification (SND) under aerobic condition.The followings were studied:1)Testing research on MICEAS system's start-up and operation at low temperature. And comparing the effect with that in normal temperature.2)Studying on the phenomena of simultaneous nitrification-denitrification in the aerobic reactor and the factors of its influencing: for example, DO concentration, COD/N of influent, the characteristic of granular sludge and the aeration mode.3)According to the study results of the forward parts,the author made a summary about the mechanism of simultaneous nitrification-denitrification.4)Studying on the simultaneous nitrification and denitrification microorganisms in MICEAS system.According to the above study, we can get that:①The average removal rate of CODcr, NH3-N, TN and TP is 87%, 64%, 60%, and 78% under the temperature between 5℃and 13℃, which supplies referenced information to deal with the wastewater in cold area.②Using the average DO concentration together with the minimum and maximum concentration, the author found that the transformation of DO in aeration times follows a kind of rule. The MICEAS system could occur obvious phenomena of simultaneous nitrification-denitrification in aerobic reactor. And the proportion of SND nitrogen removal to total denitrifying nitrogen removal was 30% upwards.③The effect of each researchful factor to organism removal is small, the removal rate under every conditions are all 80% above, whereas DO concentration, COD/N of influent, the characteristic of granular sludge and the aeration mode are all influence the effect of SND. The removal rate of nitrogen removal and ammonia nitrogen removal reached to 90.2% and 92% separately when the operation conditions is: COD/N=7, DO=0.8mg/L, reaeration DO=4mg/L, the run cycle=4h, MLSS=4000mg/L. Futhermore, in this...