Abstract：
Salinity was considered to have effects on the characteristics, performance microbial communities of aerobic granular sludge. This study investigated granulation process with gradual increase of salt under different gradients. Two identical sequencing batch reactors were operated, while the influent of Ra and Rb was subjected to stepwise increments of NaCl concentrations (0-4 g/L and 0-10 g/L). The presence of filamentous bacteria may contribute to granules formed under lower salinity conditions, potentially leading to granules fragmentation. Excellent removal efficiency achieved in both reactors although there was a small accumulation of nitrite in Rb at later stages. The removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in Ra were 95.31%, 93.70% and 88.66%, while the corresponding removal efficiencies in Rb were 94.19%, 89.79% and 80.74%. Salinity stimulated extracellular polymeric substances (EPS) secretion and enriched EPS producing bacteria to help maintain the integrity and stability of the aerobic granules. Heterotrophic nitrifying bacteria were responsible for NH4+-N and NO2--N oxidation of salinity systems and large number of denitrifying bacteria were detected, which ensure the high removal efficiency of TN in the systems.
摘要：
盐度被认为对特征有影响，好氧颗粒污泥的微生物群落性能。本研究调查了不同梯度下盐逐渐增加的造粒过程。操作两个相同的序批式反应器,而Ra和Rb的流入液经历NaCl浓度的逐步增加（0-4g/L和0-10g/L）。丝状细菌的存在可能有助于在较低盐度条件下形成颗粒，可能导致颗粒破碎。尽管在后期阶段Rb中亚硝酸盐的积累很少，但在两个反应器中都实现了出色的去除效率。化学需氧量（COD）的去除效率，总氮(TN)，Ra中总磷(TP)为95.31%,93.70%和88.66%，而相应的Rb去除率为94.19%，89.79%和80.74%。盐度刺激胞外聚合物（EPS）分泌并富集产生EPS的细菌，以帮助维持好氧颗粒的完整性和稳定性。异养硝化细菌负责盐度系统的NH4+-N和NO2--N氧化,保证了系统中TN的高去除效率。
