常温处理生活污水微氧高效颗粒污泥反应器内颗粒污泥性能研究

为了分析微氧高效颗粒污泥反应器(EGSB反应器)在环境温度下处理实际生活污水时高效稳定运行的可行性，对15~26℃常温处理实际生活污水微氧EGSB反应器内颗粒污泥活性、沉淀性能、粒径分配、形态等进行研究.结果表明，15~26℃常温处理实际生活污水微氧EGSB反应器稳定运行时颗粒污泥沉速在11~79m·h-1之间，低沉速污泥有少量上浮至三相分离器底部甚至三相分离器上部，但没有出现污泥的流失，污泥浓度达到28g·L-1（以MLSS计），可获得93.4%、83.8%、74.7%和44.0%的高COD、NH+4-N、TN和TP去除率；污泥产甲烷活性并没有降低，甚至比单纯厌氧时还有所偏高；颗粒污泥的平均粒径增大，主要集中0.63~2.00mm之间，质量分数达到了89%，既能保证反应器内的高污泥浓度，又能保证污染物质向颗粒表面和颗粒内部的高效传质，提高污染物质的转化率.颗粒污泥不同层面上微生物菌群发生了很大变化，外层丝状菌占优势，内层杆菌、丝状菌、球菌混生.微生物菌群排列紧密，细胞间紧密结合，集群协同作用使代谢物质能够以最短距离高效传递，保证了微氧EGSB反应器在常温、低浓度下的高效稳定运行.

Characteristics of granules in a highly efficient particulate biofilms reactor treating domestic wastewater at ambient temperature

In order to analyze the feasibility of highly efficient and stable operation of a micro-aerobic expanded granular sludge bed (EGSB) reactor treating actual domestic wastewater at ambient temperature (15 -26℃), the granular sludge characteristics including activity, settling, size, and morphology were investigated. The results showed that the micro-aerobic EGSB reactor could have a velocity of 11～ 79 m·h~(-1), at which a few of the granules with low settling velocity could up-flow to the bottom or even to the top of the throe-phase separator, but without any sludge washout. Thus the micro-aerobic EGSB reactor could handle a high sludge concentration of 28 g·L~(-1)with high removal efficiencies of 93.4% COD, 83.8% NH_4~+-N,74.7% TN and 44.0% TP. The specific methanogenic activity of the granular sludge in the micro-aerobic reactor did not decrease, and was even higher than in the strictly anaerobic EGSB reactor. The average granule size increased and was mainly distributed in the range of 0.63～2.00 mm with a weight percentage of 89%, which could ensure high sludge concentration and highly efficient mass transfer in the exterior and interior of the granules, which ultimately increased the pollutant removal efficiency. Under the micro-aerobic conditions, the metabolic groups of bacteria in different positions of the granules showed distinct changes. Filamentous bacteria were predominant in the peripheral layer of the granules, while the filamentous bacteria, cocci, and rod-shaped bacilli were all observed in the inner layer. Bacteria of different metabolic groups contacted closely and had a communal synergism, which could optimize the cooperation between the partner organisms and ensure highly efficient mass transfer by reducing the distance of diffusion transfer of metabolites, and ultimately ensure the highly efficient and stable operation of the micro-aerobic EGSB reactor under the conditions of ambient temperatureand low concentration.