Aerobic granular sludge membrane bioreactor (AGMBR) is highly efficient in treating urban sewage but is susceptible to membrane fouling caused by extracellular polymeric substances. In this study, we he developed five novel coagulation systems by combining commercially ailable inorganic coagulants with a self-made modified microbial flocculant (MMF), focusing on evaluating the effects of these systems on normalized fluxes, fouling resistances, wastewater quality characteristics, and membrane surface morphology. The results indicated that the compound coagulation systems had a dual impact on controlling membrane fouling in AGMBRs. Specifically, ferric chloride, polyaluminum chloride, and polyaluminum ferric chloride combined with MMF exacerbated membrane fouling by forming dense cake layers. On the other hand, the composite systems of aluminum sulfate (AS) and MMF, as well as polyferric sulfate and MMF, positively influenced membrane fouling control. Among them, AS neutralized the negative charges of colloidal particles via the positive charges of aluminum ions, thereby destabilizing and aggregating the particles. Meanwhile, the long carbon chains and numerous functional groups in MMF endow it with excellent adsorption bridging capabilities. AS/MMF was found to be the most effective in reducing both reversible and irreversible resistances through electrostatic neutralization and adsorption bridging. The superior performance of the AS/MMF system, characterized by membrane fouling mechanism as standard blocking and an increase in membrane flux associated with reduced turbidity and elevated zeta potential, was further confirmed through extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory analysis. The findings validate the efficacy of AS/MMF composite coagulation pretreatment in mitigating AGMBR membrane fouling, offering a novel solution for sustainable wastewater management.
中文翻译：
破译 AGMBR 膜污染控制的高级凝血策略：五种无机/改性微生物絮凝剂系统的比较分析
好氧颗粒污泥膜生物反应器 （AGMBR） 在处理城市污水方面非常有效，但容易受到细胞外聚合物物质引起的膜污染的影响。在这项研究中，我们通过将市售的无机混凝剂与自制的改性微生物絮凝剂 （MMF） 相结合，开发了五种新型混凝系统，重点是评估这些系统对归一化通量、抗结垢性、废水质量特性和膜表面形态的影响。结果表明，化合物凝固系统对控制 AGMBR 中的膜污染具有双重影响。具体来说，三氯化铁、聚合氯化铝和聚合氯化铁与 MMF 结合，形成致密的滤饼层，加剧了膜污染。另一方面，硫酸铝 （AS） 和 MMF 以及聚硫酸铁和 MMF 的复合系统对膜污染控制产生了积极影响。其中，AS 通过铝离子的正电荷中和了胶体颗粒的负电荷，从而使颗粒不稳定和聚集。同时，MMF 中的长碳链和众多官能团赋予了它优异的吸附桥接能力。发现 AS/MMF 通过静电中和和吸附桥接在降低可逆和不可逆电阻方面最有效。AS/MMF 系统的卓越性能，其特征是膜污染机制作为标准阻塞，并且与浊度降低和 zeta 电位升高相关的膜通量增加，通过扩展的 Derjaguin-Landau-Verwey-Overbeek （XDLVO） 理论分析进一步证实。 研究结果验证了 AS/MMF 复合混凝预处理在减轻 AGMBR 膜污染方面的功效，为可持续废水管理提供了一种新的解决方案。
