MBBR法A^2/O式工艺对污水处理厂二级出水的脱氮研究

NITROGEN REMOVAL OF SECONDARY EFFLUENT FROM WWTP BY MBBR METHOD-A^2/O PROCESS

基于污水厂二级出水中NH3-N、TN含量过高及可生化性有机碳源较低的特点,利用移动床生物膜反应器法厌氧-兼氧-好氧式(MBBR-A2/O)工艺对其进行研究。反应器采用预挂好氧膜和有机负荷递减法相结合的方式启动,通过NH3-N去除情况反应微生物的生长演化过程,并进行氮素分析。结果表明,反应器启动分为3个阶段,微生物适应阶段、微生物活性提高阶段和微生物活性稳定阶段,在低碳源的条件下,反应器经50 d挂膜启动成功,对NH3-N去除率达到85%以上;在稳定运行阶段,对NO2--N、NO3--N、TN的去除率分别为68.9%、58.1%、69.9%,说明通过A2/O反应器串联运行,系统内存在同步硝化反硝化作用,达到强化脱氮的目的。

Based on the characteristics of sewage plant＇s secondary effluent with excessive ammonia nitrogen,total ammonia nitrogen and lacking of biodegradability organic carbon source,MBBR method-A2/O process（aka.Anaerobic-facultative anaerobic-aerobic moving bed biofilm reactor） was studied here.The reactor is launched by combining aerobic precoating and organic load descending method,and the nitrogen analysis was conducted according to evolution process of microorganism through the removal of ammonia nitrogen in this project.The results showed that launching process of the reactor can be divided into three phases,microorganism adaptation phase,microbial activity raise phase,and microbial activity stabilization phase.On the condition of low carbon source,the reactor＇s biofilm formation launched successfully over the period of 50 d,and with 85% of ammonia nitrogen removal rate.In the stage of steady operation,the removal rate of NO2--N,NO3--N and TN are 68.9%,58.1%,69.9% respectively.In order to strengthen denitrification,the series operation of anaerobic-facultative anaerobic-aerobic reactors were performed,and synchronous nitrification and denitrification were taken place inside of the system.