改良UCT分段进水深度脱氮除磷工艺反硝化动力学性能

The Denitrification Dynamics of Modified UCT Step Feed Enhanced Biological Nutrients Removal Process

采用序批试验研究了在T=(15±1)℃条件下以生活污水、污泥水解酸化上清液、乙酸钠、甲醇、乙醇和葡萄糖为电子供体的活性污泥的反硝化性能以及pH变化规律和动力学特性.结果表明,乙酸钠的比反硝化速率和比耗碳速率最高,分别为4.13 mg/(g.h)和29.8 mg/(g.h),但其反硝化能力最低.污泥水解酸化上清液的反硝化速率与乙酸钠相当.反硝化菌需经若干周期的驯化后才能适应甲醇和乙醇电子供体.当要求直接提高反硝化速率时,不宜选择甲醇和乙醇为碳源.而葡萄糖电子供体系统在前10～120 min出现短暂的'ρ(NOx--N)还原停滞平台',当大分子葡萄糖糖酵解为小分子有机物后,反硝化过程才顺利进行,糖酵解过程是葡萄糖反硝化过程的限速步骤.此外,不同电子供体反硝化过程pH变化规律可以间接指示反硝化动力学特性,其缺氧异养菌产率系数为0.68～0.73.

Batch experiments are conducted to investigate the denitrification prosperities,denitrification dynamics and pH variation with municipal wastewater,supernatants of sludge hydrolyzed acidification,acetic sodium,methanol,ethanol and glucose as electron donors as well as nitrate as electron acceptor under T=（15±1）℃.The results show that the maximum specific denitrification rate and specific organic compounds utilization rate,which is 4.13mg/h and 29.8mg/h,respectively,were attained when acetic sodium is used as the electron donor,whereas the lowest denitrification potential was also observed.As for supernatants of sludge hydrolyzed acidification,its denitrification performance is nearly as same as acetic sodium.Furthermore,denitrification bacteria can adapt to methanol and ethanol until a period of sludge acclimations,so these two electron donors could not be used as soon as it needed to improve the denitrification efficiency.As for glucose,there is a ＂ρ（NO-x-N） reduction stop platform＂ during 10-120mins of reaction process,after glucose molecules decomposing into small molecules organisms the denitrification could go on successfully,so glycoside is the rate-limiting step of denitrification with glucose as the electron donor.Besides,pH indicates the denitrification characteristics of different electron donors with heterotrophy anoxic yields of 0.68-0.73.