好氧颗粒污泥处理含盐生活污水的特性

Treatment of Saline Domestic Sewage by Aerobic Granular Sludge

含盐生活污水的盐度会引起活性污泥系统微生物菌群结构的变化,进而影响对污水的脱氮除磷效能。由于好氧颗粒污泥内部传质和传氧的限制,使得处于其内部的微生物可以有效抵御高盐度及盐度变化对污泥系统产生的冲击,从而达到高盐度生活污水脱氮除磷的目的。经过35 d的培养,形成了结构紧密的好氧颗粒污泥,并表现出良好的沉降性能和较高的生物量。在好氧颗粒污泥形成过程中,短程硝化现象明显,胞外聚合物中的蛋白质含量明显升高,达到37.0 mg/gMLSS,蛋白质与多糖的比值为1.72,说明蛋白质是好氧颗粒污泥形成的重要因素。培养成熟的好氧颗粒污泥对含盐生活污水具有较高的处理效能,但短程硝化现象消失,对NH+4-N和PO3-4-P的去除率分别达到87.3%和68.9%,在好氧颗粒污泥的生物除磷过程中PHB起主要作用。荧光原位杂交检测结果表明,在好氧颗粒污泥形成阶段AOB为优势菌群,当好氧颗粒污泥培养成熟后,虽然PAO数量多于GAO,但是PAO也未在好氧颗粒污泥系统中占据优势。

The salinity in saline domestic sewage can lead to variations of microbial community in activated sludge and consequently the nitrogen and phosphorus removal efficiency. Due to barriers of mass and oxygen transfer inside aerobic granular sludge, the inner microorganisms can effectively tolerate high salinity and the impact of salinity variation, therefore accomplishing simultaneous nitrogen and phosphor- us removal in saline domestic sewage treatment. Aerobic granular sludge （AGS） with compact structure was obtained after 35 d cultivation, and good settleability and high biomass concentration were observed. Short-cut nitrification occurred in the formation process of AGS. In addition, protein content in extracel- lular polymeric substances （EPS） increased significantly to 37.0 mg/gMLSS polysaccharide ratio was 1.72, which indicated that protein was an important and the total protein/total factor in AGS formation.Short-cut nitrification disappeared when AGS matured, and the removal rates of NH4＋ - N and PO4^3- - P were 87.3% and 68.9% , respectively. Polyhydroxybutyrate （PHB） was considered a key factor in biological phosphorus removal. FISH results demonstrated that AOB was dominant in AGS formation. When AGS matured, there were more PAO than GAO, but PAO was not dominant in aerobic granular sludge.