Wang Mengfei, He Junguo, Dong Xiangke, Zhang Ruimiao
School of Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.
School of Civil Engineering, Guangzhou University, Guangzhou 510006, China.
J Environ Sci (China). 2025 Jan;147:404-413. doi: 10.1016/j.jes.2023.11.022. Epub 2023 Nov 29.
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 NH-N and NO-N oxidation of salinity systems and large number of denitrifying bacteria were detected, which ensure the high removal efficiency of TN in the systems.
盐度被认为会对好氧颗粒污泥的特性、性能及微生物群落产生影响。本研究在不同梯度下随着盐度的逐渐增加对颗粒化过程进行了研究。运行了两个相同的序批式反应器，而反应器Ra和Rb的进水NaCl浓度逐步增加（分别为0 - 4 g/L和0 - 10 g/L）。丝状菌的存在可能有助于在低盐度条件下形成颗粒，但可能导致颗粒破碎。尽管后期Rb中有少量亚硝酸盐积累，但两个反应器均实现了优异的去除效率。反应器Ra中化学需氧量（COD）、总氮（TN）和总磷（TP）的去除效率分别为95.31%、93.70%和88.66%，而Rb中相应的去除效率分别为94.19%、89.79%和80.74%。盐度刺激了胞外聚合物（EPS）的分泌并富集了产生EPS的细菌，有助于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中NH-N和NO-N的氧化，并且检测到大量反硝化细菌，这确保了系统中TN的高去除效率。
