A novel Anaerobic Cathodic Dynamic Membrane Bioreactor (AnCDMBR) for efficient mitigating fouling and recovering bioenergy from municipal wastewater

• Published in: Water research (Oxford) 2024-11, Vol.265, p.122225, Article 122225
• Main Authors: Sun, Xinyi, Chen, Mei, Li, Yanli, Wang, Jinning, Zhang, Minliang, Li, Nan, Dai, Ruobin, Wang, Zhiwei, Wang, Xin
• Format: Article
• Language: English
• Subjects: Anaerobic dynamic membrane bioreactor; Anaerobiosis; Antifouling; Bioreactors; Electrodes; Electrostimulation; Energy recovery; Membranes, Artificial; Methane; Municipal wastewater treatment; Waste Disposal, Fluid - methods; Wastewater - chemistry
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2024.122225

•Cathodic dynamic membrane (CDM) was developed to treat wastewater in AnMBR (AnCDMBR).•Well-controlled fouling and efficient separation were observed in CDM with low cost.•AnCDMBR achieved superior CH4 yield rate of 0.26 L-CH4/g-COD with high purity (>95 %).•Enhanced metabolism and spatially heterogeneous microbiota promote bioenergy recovery.•It shows significant potential for AnCDMBR in municipal wastewater treatment. Concerns regarding membrane fouling and suboptimal bioenergy recovery have constrained the implementation of anaerobic membrane bioreactor (AnMBR) for treating low-strength municipal wastewater. This study presents a novel anaerobic cathodic dynamic membrane bioreactor (AnCDMBR) designed to address these challenges. A self-formed cathodic dynamic membrane (CDM) on inexpensive carbon cloth was developed to function as both a membrane and biocathode to achieve dual-function effects of mitigating membrane fouling and accelerating organics conversion. Compared with common dynamic membrane (1.52 kPa/d) and commercial membranes (7.52 kPa/d), the developed CDM presented a significantly reduced fouling rate (1.02 kPa/d), exhibiting the potential as a substitute for high-cost conductive membranes. Furthermore, efficient and stable biomethanation occurred in AnCDMBR with a superior methane yield rate of 0.26 L-CH4/g-COD (CH4 content > 95 %), which was 1.42 times higher than the control, linked to the higher activities of microbial metabolism and methanogenic-related key enzymes. Further analysis revealed that electrostimulation-induced niche differentiation of microbiota regulated interspecies interactions between electroactive microorganisms and complex anaerobic digestion microbiomes, facilitating organic matter conversion to methane and leading to superior bioenergy recovery. This study offered a new strategy for effectively mitigating fouling and recovering bioenergy from low-strength wastewater, potentially expanding the application of AnMBRs. [Display omitted]