SBR后置缺氧反硝化除磷的启动及去除性能

为实现对氮磷的高效同步去除,采用将缺氧后置的SBR工艺,以生活污水为处理对象,考察反硝化除磷工艺的启动与运行效果.结果表明,先通过短污泥龄(SRT)驯化富集聚磷菌(PAOs),再延长污泥龄并引入缺氧段,39d即可实现反硝化除磷工艺的启动,COD、TP、NH₄⁺-N、TN去除率分别为92.9%、98.4%、100%和87.6%.进水COD与TN比(C/N)对系统氮磷去除有一定影响:C/N短暂的降低幅度不超过17.65%时,氮磷去除效率并没有明显变化;当超过33.3%时,脱氮除磷性能下降,但伴随着运行时间的延长,出水COD浓度减少,反硝化除磷菌(DPAOs)在PAOs比例也会提升,这在一定程度上弥补了DPAOs反硝化脱氮效率的下降.周期实验表明,pH值与DO可以作为厌氧释磷结束与周期结束的实时控制参数,大大缩短反应时间,降低曝气能耗.

The start-up and performance of denitrifying phosphorus removal process in a post-anoxic SBR system

In order to realize efficient simultaneous nitrogen and phosphorus removal in domestic wastewater, a post-anoxic SBR system was used. The results showed that the denitrifying phosphorus removal process was launched in 39days by firstly shortening the SRT to enrich phosphorus accumulating organisms (PAOs), and then extending the SRT and introducing the anoxic phase. COD, TP, NH₄⁺-N and TN removal efficiency were 92.9%, 98.4%, 100% and 98.4%, respectively. The effect of influent carbon-nitrogen ratio (C/N) was also investigated. There was no obvious change on nitrogen and phosphorus removal efficiency when the decrease of C/N was below 17.65% in a short term. When it exceeded 33.3%, the system had a bad performance on both nitrogen and phosphorus removal, but in the long run, the effluent COD concentration fell, and the proportion of denitrifying phosphorus accumulating organisms (DPAOs) in PAOs increased, which supplemented the removal efficiency of decline to some extent. The cycle test indicated that pH and DO can be the real-time control parameters which decided whether the anaerobic phosphorus release and the cycle ended or not. The reaction time and energy consumption of aeration could be reduced significantly.