好氧颗粒污泥处理市政污水性能与微生物特性研究

以成熟好氧颗粒污泥（AGS）为接种污泥，在序批式反应器（SBR）中考察其对低浓度市政污水的处理效能、污泥特性及微生物多样性的变化.结果表明，在低有机负荷（进水COD为179~212 mg·L^-1）、高溶解氧（DO>5 mg·L^-1）条件下，系统出水COD低于50 mg·L^-1，NH₄⁺-N浓度稳定在0.7~0.8 mg·L^-1，但脱氮除磷效能有待优化.体系中0.2~0.6 mm的污泥颗粒最为稳定，运行期间污泥SVI₃₀值始终保持在32~40 mL·g^-1，呈现出良好的沉降性能.系统中少量絮状污泥的存在对AGS的稳定性是有利的，本试验条件下，<0.2 mm污泥体积占比约为30%时AGS体系稳定运行.胞外聚合物（EPS）中蛋白质（PN）含量增加与AGS的稳定性呈正相关，可见PN对AGS稳定运行起着重要作用.微生物高通量测序结果表明，Proteobacteria和Bacteroidetes为主要菌门；运行过程中有利于硝化作用的Gammaproteobacteria逐渐成为优势菌纲；系统中存在促进EPS分泌和有机污染物去除的黄杆菌属（Flavobacterium）和陶厄氏菌属（Thauera），这有利于AGS的稳定运行，同时也存在硝化螺旋菌属（Nitrospira）、陶厄氏菌属（Thauera）、副球菌属（Paracoccus）、梭菌属（Fusibacter）、变形菌属（Proteocatella）等脱氮除磷功能菌属，但需优化运行参数强化同步脱氮除磷效能.本研究结果对AGS系统处理实际市政污水的稳定运行具有重要的指导意义.

Performances and microbial properties of aerobic granular sludge treating municipal wastewater treatment

With the mature aerobic granular sludge (AGS) as seed sludge, the treatment efficiency, sludge characteristics and microbial diversity were investigated when treating actual municipal wastewater in sequencing batch reactor (SBR). The results showed that the effluent COD concentration was lower than 50 mg·L^-1 and the effluent NH₄⁺-N concentration stabilized at 0.7~0.8 mg·L^-1 under the condition of low organic loading rate(intake COD about 179~212 mg·L^-1) and high dissolved oxygen (DO>5 mg·L^-1). However, the nitrogen and phosphorus removal efficiency needed to be optimized. The granular sludge with size of 0.2~0.6 mm revealed strong stability in the system. And The sludge showed good settleability with the sludge volumetric index (SVI₃₀) of 32~40 mL·g^-1 during the operation. The results also proved thatthe existence of small amounts of flocculent sludge seemed to be beneficial to the AGS stability. Under the experimental conditions, the system performed well and stably with 30% sludge with the size of less than 0.2 mm. The positive correlation between content of polymeric protein (PN) in extracellular polymeric substances (EPS) and AGS stability indicated the important effect of PN on stable operation of AGS syetem. The results of microbial high-throughput sequencing analysis exhibited that Proteobacteria and Bacteroidetes was predominant at phylum level. At genus level, Flavobacterium and Thauera contributed to the EPS secretion and organic pollutants removal, thus playing an important role to the stable operation of AGS. At class level, Gammaproteobacteria beneficial to nitrification gradually became the dominant class during the operation. In addition, there were different nitrogen and phosphorus removal bacteria in the system mainly including Nitrospira, Thauera, Paracoccus, fusibacter, proteocatella, etc.. Nevertheless, the operation of AGS system needed to be optimized to strengthen simultaneous nitrogen and phosphorus removal. The experimental results in this paper can provide significant guidances to the stable operation of AGS system treating actual municipal wastewater.