This study addressed a less-reported issue: the insufficient alkalinity encountered when anaerobic membrane bioreactors (AnMBRs) are used to treat municipal wastewater (MWW). In the present study, a 20-L AnMBR was initiated at an MWW treatment plant. During the initial startup, a continuous decrease in pH was observed. Through the analyses of the balance between HCO3–/CO2 in the biogas and alkalinity in the reactor, the cause of pH instability was determined to be that the alkalinity could not balance the acidity induced by the continuous dissolution of CO2 from biogas in the liquid phase. Therefore, this study employed the in-situ removal of CO2 from biogas using soda lime to reduce the CO2 partial pressure, thereby achieving stable control of the pH in the reactor. This study provides valuable experience and technical support for anaerobic processes for treating low-alkalinity MWW in the future applications.

中文翻译：

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使用厌氧膜生物反应器从沼气中去除 CO2 改善了低碱度城市污水的稳定处理


这项研究解决了一个较少报道的问题：使用厌氧膜生物反应器 （AnMBR） 处理城市废水 （MWW） 时遇到的碱度不足。在本研究中，在 MWW 处理厂开始使用 20 L AnMBR。在初始启动期间，观察到 pH 值持续降低。通过分析沼气中 HCO3–/CO2 与反应器中碱度之间的平衡，确定 pH 值不稳定的原因是碱度无法平衡液相中 CO2 从沼气中持续溶解所引起的酸度。因此，本研究采用碱石灰原位去除沼气中的 CO2 来降低 CO2 分压，从而实现对反应器中 pH 值的稳定控制。本研究为未来应用中处理低碱度 MWW 的厌氧工艺提供了宝贵的经验和技术支持。