不同电子受体反硝化除磷脱氮性能研究

Research on the Characteristics of Denitrifying Phosphorus and Nitrogen Removal by Different Electron Acceptors

目的研究以硝酸氮和亚硝酸氮为电子受体时,污水中氮磷的去除效果.方法采用两个厌氧/缺氧SBR反应器（1^#和2^#）处理配制的含磷污水,每个反应器的有效容积为16 L,反应周期为6.5 h,污泥龄为32 d,运行方式采用SBR反应器,一次集中进水-厌氧搅拌（2 h）-缺氧搅拌（4 h）-沉淀（0.5 h）-排水.在缺氧时段开始时,1^#反应器一次性投加硝酸钠,2^#反应器投加亚硝酸钠.每天运行两个周期.结果反应器运行2～3周之后,可以维持比较稳定的同步脱氮除磷效果,反硝化除磷反应器启动成功.1^#反应器总磷的平均去除率为69%,硝酸氮的平均去除率为89%,2^#反应器总磷的平均去除率为75%,亚硝酸氮的平均去除率为91%.以硝酸氮为电子受体时,一部分硝酸氮转化成亚硝酸氮,进而两者共同发挥电子受体的作用,去除污水中的氮和磷.结论硝酸氮和亚硝酸氮都可以作为除磷的电子受体,在缺氧条件下实现同步脱氮除磷,并且亚硝酸氮作为电子受体时的脱氮除磷效率高于硝酸氮.

In order to investigate the characteristics of removing phosphorus and nitrogen in wastewater with nitrate and nitrite nitrogen as electron acceptors, two anaerobic/anoxic sequencing batch reactors were adopted to treat compounded wastewater containing phosphorus. Each reactor is with 16 L valid volume,6. 5 h reaction period and 32 days SRT. The operating method was as follows：concentrated inlet-anaerobic agitation （ 2 h） - anoxic agitation （4 h） - sedimentation （0. 5 h） - decanting. At the beginning of anoxic phase, sodium nitrate was put into one reactor （ No. 1 ）, and sodium nitrite into another reactor （ No. 2 ）. The reactors were run for two periods each day. The reactors could steadily remove nitrogen and phosphorus simultaneously after 2-3 weeks since beginning, which showed that the reactors were started up successfully. The average ratios of removing total phosphorus and nitrate nitrogen in the reactor of No. 1 were 69% and 89% ,respectively. And the average ratios of removing total phosphorus and nitrite nitrogen in the reactor of No. 2 were 75% and 91% ,respectively. Partial nitrate nitrogen was transformed to nitrite nitrogen while it was served as electron acceptor, and they played the role of electron acceptors together to remove nitrogen and phosphorus in wastewater. It is concluded that both nitrate nitrogen and nitrite nitrogen can be served as electron acceptors to remove phosphorus, and they can remove nitrogen and phosphorus simultaneously in anoxic condition. Moreover, the efficiency of removing nitrogen and phosphorus by nitrite nitrogen is higher than that by nitrate nitrogen.