Research On Municipal Wastewater Treatment Using MOCO System

Based on analyzing theories and techniques for nitrogen and phosphorus removal, summing up technical characteristics of OCO reactor, we modified OCO to form MOCO by experiments. MOCO is a denitrification and phosphorus removal system, including anaerobic area, anoxic area and aerobic area.The followings were studied:(1) Testing research on OCO system's start-up and operation at low temperature(2) Testing research on modifing C Partition Wall in Anoxic Zone(3) Testing research on Setting Guild Wall to Adjust Mixed Liquor Reflux(4) Determination of parameters for MOCO used in treating municipal wastewater(5) Establish and evaluate kinetic model of the biological nitrogen removal and biological phosphorus removal processAccording to the above study result: 1) when the C partition wall is extended by 60°, average removal ratio of COD TN TP is increased to 86%,63%, 78%from original 83%,49%,70%. The main reason for the increase of all the removal ratios is that: anoxic area is enlarged, so retention time in anoxic area is prolonged, nitrification is more thorough, and nitrogen removal effect is increased..2) The backflow quantity are controlled effectively through the adjustment of the guide wall, the potential of denitrification in the anoxic is fully exerted to make TN in the effluent decrease obviously. Simultaneity, less NO_X-N can be taken back to anaerobic area. It is good for phosphor release and removal. After superimposing the guide wall, the stirrers in the 2 and 3 aeras ingress can be taken off, and the energy. Of system is decrease. According to the test, when one end of guide wall was located at position 2(b/a=2/3～ 3/4), the system has the highest removal rates.3) MOCO is effective in phosphorous removal and denitrification and COD removal. The COD, TP ,TN in outflow can decrease to 12～30mg/L, 0.12～0.47mg/L, 5.63～9.35mg/L under the normal test water quality. According to the test study, the best running parameter of MOCO are : (a) Volumetric ratio of anaerobic, anoxic and oxic zones (calculated as the volume of cirque) of MOCO oxidation ditch is about 1: 3.2: 4.6. The radian of C partition wall is 240°(180°+60°)(b) Total hydraulic retention time of the system is 9～10hrs, sludge age is 18～22 days, DO concentration at the middle part of aeration reactor is 2.0～2.5mg/L, and sludge loading of COD is about...