长期饥饿后SPNA微颗粒污泥系统性能恢复

Performance recovery of SPNA micro-granular sludge system after long-term starvation

为了确定长期饥饿后连续流一段式部分亚硝化-厌氧氨氧化(SPNA)工艺的性能恢复情况,采用连续流反应器,考察了在室温下(11~23℃)经历161d饥饿期的SPNA系统性能恢复策略的可行性及脱氮性能和菌群结构变化.通过控制DO浓度及进水氨氮负荷,逐渐实现亚硝酸盐氧化菌(NOB)的抑制和淘汰、氨氧化菌(AOB)和厌氧氨氧化菌(An AOB)的活性恢复和富集.在68d内系统总氮去除率恢复至72.13%,氨氮去除率恢复至94.75%.微颗粒污泥(≥200μm)的占比从42.04%升至60.98%.微生物群落结构分析发现,停止运行161d后系统Candidatus Kuenenia的相对丰度升至25.53%,表现出较强的抵抗饥饿条件的能力,系统恢复后其相对丰度逐渐降低,接近反应器饥饿前水平.AOB的高底物利用能力是系统恢复的前提,An AOB活性的提高是系统恢复的关键.系统性能的成功恢复表明室温下161d饥饿期对系统造成的影响是可逆的,长期室温下储存SPNA污泥是可行的.

In order to determine the performance recovery of single-stage partial nitritation anammox(SPNA) process after long-term starvation, a continuous flow reactor was used in this study, to investigate the feasibility of the recovery strategy, nitrogen removal performance and microbial community structure variations of SPNA system undergoing 161 d starvation at room temperature(11~23℃). By controling DO concentration and influent ammonia nitrogen load, the inhibition and elimination of nitrite oxidizing bacteria(NOB) and the recovery and enrichment of ammonium oxidation bacteria(AOB) and anaerobic ammonium oxidation bacteria(An AOB) were gradually realized. Within 68 days, the removal efficiency of total nitrogen and ammonia nitrogen increased to 72.13% and 94.75% respectively. The proportion of micro-granular sludge(≥200μm) increased from 42.04% to 60.98%. The analysis of microbial community showed that the relative abundance of Candidatus Kuenenia increased to 25.53% after 161 days starvation,which showed that Candidatus Kuenenia has a stronger hunger tolerance. After the system recovery, the relative abundance of Candidatus Kuenenia gradually decreased to the level before the reactor starvation. The higher substrate utilization ability of AOB is the premise of system recovery, and the improvement of AnAOB activity is essential for system recovery. The successful recovery of the system performance showed that the starvation period of 161 d at room temperature has reversible effect on the system, and it is feasible to store SPNA sludge at ambient temperature for a long time.