Integrated Technology Research Of Small Towns Sewage Treatment Based By Improved A~2/O

With the rapid growth of population and the rapid development of economy society,the total amount of sewage discharge in China is increasing year by year. In view of small towns and villages where the drainage pipe network develop backward, first and second tier cities which badly need construct reclaimed water reuse project, it is of great significance to research and develop the small integrated wastewater treatment equipment. This study adopted domestic wastewater as the research object, designed and constructed integrated wastewater treatment equipment. which base on a combination of the improved A2/O for technical research.First of all, the wastewater got into pre anoxic and anaerobic stage according to a certain percentage, the equipment reaction tank set up partition plates to block alternately, adopted the wave pump to stir and push the flow to form good water conditions. In spring, when system startup and operate stablely, the effluent quality are stable, COD were no more than 49 mg/L, TP were no more than 0.48 mg/L, TN were no more than 14.3 mg/L, ammonia nitrogen were no more than 0.9 mg/L.Secondly, aerobic adopted three segments MBBR Segmented oxygen supply. The first aerobic section and the tail section adopted a cylindrical form, the middle was in the form of channel. The secondary tank and the main reaction pool were builted together. By conducting single factor experiment, determined the best dissolved oxygen concentration of each section of the aerobic segment, respectively is: the first segment 3~4.5 mg/L, middle 2~3 mg/L, terminal 1~2 mg/L. Compare Water treatment effect between uniform oxygen supply and Segmented oxygen supply, found that the effluent COD concentration under Segmented oxygen supply is slightly higher than the conditions of uniform oxygen supply, the effluent COD concentration are all lower than 35 mg/L; The effluent concentration of TP are basically the same;The effluent concentration of ammonia nitrogen、TN under segmented oxygen supply is lower than under uniform oxygen supply. The segmented oxygen supply can save energy and reduce operating costs in the premise of ensuring the water treatment effect.Finally, the summer effluent COD, ammonia nitrogen, TN, TP meet “the urban sewage treatment plant pollutant discharge standard "(GB18918-2002) level of A standard. The winter effluent COD. ammonia nitrogen, meet “the urban sewage treatment plant pollutant discharge standard "(GB18918-2002) level of A standard, the winter effluent TN, TP meet level of B standard. The summer and winter effluent quality meet the water quality standard of the life of mixed water(CJ25.1-89). In winter and summer, System equipment have high stability, good impact resistance.Considering one-time investment and operating management costs of equipment, the integrated wastewater treatment equipment. which base on a combination of the improved A2/O treat Small town sewage. The device has outstanding advantages in the water treatment effect and energy saving. It provides reference for the research of the same kind of equipment and has guiding significance.