Experimental Study Sndmbr Treatment Of Urban Sewage

With our county’s rapid economic development and the gradual increase of the level of urbanization, nitrogen and phosphorus in the domestic sewage have significantly increased. Research to develop a new and efficient domestic sewage treatment technology has great significance in the case of the rising discharge standards. This experiment used MBR to remove COD and nitrogen in the domestic wastewater,and remove the phosphorus in the same time,in order to make some research and exploration in the domestic wastewater treatment and reuse.This paper used the membrane bioreactor urban sewage processing, mainly on the MBR process of simultaneous nitrification and denitrification (SND) and phosphorus removal under different operating factors.Test proved that the DO was an important factor of affecting the membrane bioreactor in the SND and phosphorus removal, when the oxygen concentration in the reactor was low and DO was1.0mg/L, the effect of system processing was better, and when the HRT was controlled at about6h, C/N of about8, and pH was slightly alkaline at the same time, the MBR had a good simultaneous nitrification and denitrification effect. And when the concentration of COD and NH3-N of influent was178.9～398.2mg/L and39.2-53.9mg/L, the removal efficiencies of COD、NH3-N and TN can achieve89.43%、80.5%and75.72%.SRT has a great effect on SND and the removal of TP in the MBR working process,so the test was divided into two parts in accordance with different control the sludge age and found that, in the long mud run, when the operational factors are controlled in the best conditions, the system of nitrification and denitrification capacity gradually increase,ammonia and TN have gradually increased, and phosphorus emissions from the MBR within the anaerobic phosphorus release can not be out through the sludge removal system, resulting in effluent TP concentration slightly higher than a standard urban sewage. Through the mud test, we found that if the sludge age was controled between30～40d, we can effectively solve the contradiction about sludge age between the denitrification bacteria and phosphorus removing bacteria,the removal efficiencies of phosphorus can achieve80.61%,and the effluent concentration was under1.40mg/L, MBR system had been a good simultaneous nitrification and denitrification nitrogen removal and phosphorus removal effect.In addition, the later test was on membrane fouling. The results showed that with the advance of MBR running time. the membrane fouling condition was gradually deteriorated, the membrane surface of inorganic had substances and micro-colloidal precipitates, and had the existence of filamentous bacteria and Staphylococcus biological contamination. In the membrane cleaning process, had used NaCIO and oxalic acid solution to clean the membrane, the membrane flux recovery rate arrived90.5%.