Research And Development Of The New Technology And Demonstration Project For Sludge Reduction Of The Demestic Sewage Treated By Composite Biological Method With Denitrogenation Filler

With the economic development, the amount of sewage is increasing.currently the effective way to deal with the sewage is activated sludge method, but the drawback is easy to produce large amounts of sludge,then increasing the cost of various sewage treatment plant effluence. This topic using composite biological processes which combination of activated sludge and biofilm, the use of a new type of denitrification filler added to the activated sludge process composed of dual sludge system for domestic wastewater treatment and sludge reduction research, by small pilot test in the laboratory and on-site sewage treatment plant commissioned data analysis to calculate the composite biological process, activated sludge and biofilm in the whole process plays important role in the process of removal of organic matter and ammonia for sludge reduction has contributed to China’s western county sewage treatment plant as a demonstration project has made gratifying achievements.The results indicate that:(1) Small test process using the wastewater treatment plant as influent water in aeration reactor at a reflux ratio of100%, HRT was7h conditions, CODcr、NH3-N、 SS removal efficiency reached83%,97%,95%, effluent quality could reach the first level A criteria specified in Discharge national Standard. With ammonia as the substance calculation, the apparent growth rate Yobs sludge was0.079kgMLSS/kgNH3-N-d, complex biological activated sludge and biofilm Yobss and Yobsb were0.023,0.093kgMLSS/kgNH3-N·d. To COD as the substance for calculating Yobs0.073kgMLSS/kgCODcr-d, Yobss and Yobsb were0.022,0.223kgMLSS/kgCODcr-d.(2) Pilot process using sewage A2/O reactor simulation site process, examine the continuous flow condition of pollutants removal, sludge reflux ratio is set to100%, the mixture reflux ratio of200%, HRT7h when the experimental results show CODcr, NH3-N, TN removal efficiency reached90%,96%,95%, effluent quality can achieve an A national emission standards. Calculate the apparent yield coefficient Yobs to0.0998kgMLSS/kgCODcr·d.(3) Since the treatment scale of the sewage treatment plant was expanding, the Carrousel oxidation ditch treatment process was not suitable for the current trend. In addition, the ammonium of effluent was exceeded more seriously as a result of the unstable operation processes. Based on the comprehensive analysis of existing operational processes and the pre-expanding pool, the performance of composite biological processes(by adding efficient denitrogenation filler) was investigated for sludge reduction and higher operational efficiency. After more than four months’ operation, the results showd that the effluent of the new process can met the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002). Also, the removal efficiency of ammonia nitrogen was dramatically improved, and the removal efficiency of ammonium and COD was up to95%and91%, respectively. However, the yield coefficient sludge process was significantly reduced to only0.134kgMLSS/kgCODcr-d, which has positive meaning for the sludge reduction in urban wastewater treatment. Lower than conventional activated sludge treatment of domestic sewage0.6kgMLSS/kgCODcr-d significantly reduced. Taking advantage of the activated sludge treatment of domestic sewage and make up for the shortcomings large amount of excess sludge by biofilm method. As a demonstration project can provide experience for the upgrading of other sewage treatment plants.