好氧/缺氧交替间歇饥饿CANON工艺处理生活污水

Treatment of domestic sewage by CANON process under alternate oxic/anoxic intermittent starvation

为探究CANON工艺处理实际生活污水的稳定性,采用SBR反应器,接种实验室稳定运行的CANON污泥,以实际生活污水为进水。实际生活污水水质复杂、含有有机碳源、氨氮含量低,带来NOB和异养菌(如反硝化菌)大量繁殖的问题,针对这一情况需要改善工艺运行参数,采用水力筛分好氧/缺氧交替间歇饥饿方式运行反应器。在连续动态实验中,反应器以3 d饥饿和3 d恢复为一个周期运行,在间歇饥饿期间,R1和R2排出的絮状污泥分别采用1∶1和2∶1两种曝停比进行好氧/缺氧交替间歇饥饿,第50天时,两个反应器的自养脱氮贡献率均超过80%,而反硝化途径的贡献率小于1%。采用水力筛分好氧/缺氧交替强化间歇饥饿的方式,有效地抑制了系统中的NOB及反硝化菌。最终氨氮去除率分别稳定在87.78%和94.14%,总氮去除率则分别达到75.59%和82.07%,实现了CANON工艺处理低氨氮生活污水的稳定运行。生活污水培养的CANON污泥颜色较深,第50天时,R1和R2反应器的体积平均粒径分别达673和659μm,EPS质量分数受总氮质量浓度和有机碳源等多个因素影响,保持缓慢增长的趋势。

To explore the stability of the completely autotrophic nitrogen removal over nitrite(CANON)process in the treatment of actual domestic sewage,sequencing batch reactor(SBR)was used to inoculate the CANON sludge that is stably operated in the laboratory,and actual domestic sewage was used as the influent.Actual domestic sewage has complex water quality,contains organic carbon sources,and has low ammonia nitrogen content,which brings about the problem of proliferation of nitrite-oxidizing bacteria(NOB)and heterotrophic bacteria(such as denitrifying bacteria).It is necessary to improve the operating parameters in response to this problem.In this work,the CANON reactor was operated in a hydraulic screening and alternate oxic/anoxic intermittent starvation mode.In continuous dynamic experiment,the reactors ran in a cycle of 3 d starvation and 3 d recovery.During intermittent starvation,two alternate oxic/anoxic ratios(1∶1 and 2∶1)were adopted for the flocculent sludge discharged by R1 and R2 for oxic/anoxic intermittent starvation.The contribution rate of autotrophic denitrification of both reactors exceeded 80%,while that of the denitrification pathway was less than 1%on the 50 th day.The alternate oxygen intensification of intermittent starvation effectively inhibited NOB and denitrifying bacteria in the system.The final ammonia nitrogen removal rate was stabilized at 87.78%and 94.14%,and the total nitrogen removal rate reached 75.59%and 82.07%respectively,which can realize the stable operation of CANON process for domestic sewage treatment with low ammonia nitrogen.The CANON sludge cultured by domestic sewage had a darker color.On the 50 th day,the volume average particle size of the R1 and R2 reactors reached 673 and 659μm respectively.The mass fraction of extracellular polymeric substance(EPS)was affected by multiple factors such as total nitrogen concentration and organic carbon source,and maintained a trend of slow growth.