The productivity and efficiency of two-chamber microbial electrolysis cell and anaerobic digestion integrated system (MEC-AD) were promoted by a complex of anaerobic granular sludge and iron oxides (Fe-AnGS) as inoculum. Results showed that MEC-AD with Fe-AnGS achieved biogas upgrading with a 23%-29% increase in the energy recovery rate of external circuit current and a 26%-31% decrease in volatile fatty acids. The energy recovery rate of MEC-AD remained at 52%-57%, indicating a stable operation performance. The selectively enriched methanogens and electroactive bacteria resulted in dominant hydrogenotrophic and acetoclastic methanogenesis in the cathode and anode chambers. Mechanistic analysis revealed that MEC-AD with Fe-AnGS led to specifically upregulated enzymes related to energy metabolism and electron transfer. Fe-AnGS as inoculum could improve the long-term operation performance of MEC-AD. Consequently, this study provides an efficient strategy for biogas upgrading in MEC-AD.

2023-08-01·Bioresource Technology

Boosting resilience of microbial electrolysis cell-assisted anaerobic digestion of blackwater with granular activated carbon amendment

Article

作者: Dhar, Bipro Ranjan ; Huang, Qi ; Liu, Yang

Poor hydrolysis and methanogenesis efficiencies remain the main challenges for blackwater anaerobic digestion. This study investigated the performance of a granular activated carbon (GAC) amended microbial electrolysis cell-assisted anaerobic digester (MEC-AD) treating blackwater. Due to hydrolysis limitation, both MEC-AD and control reactors experienced performance declines as the organic loading rate increased from 3.0 to 4.5 g COD/L-d. Then, adding GAC without mixing formed GAC-sludge aggregates that improved methane yield to 38.3% and 32.3% in the MEC-AD and control reactor, respectively, and enhanced hydrolysis efficiency. The amended MEC-AD also successfully overcame the performance deterioration due to a temperature drop. Biomarker identification revealed the crucial roles of GAC biofilms and settled sludge in promoting methanogenesis and hydrolysis, respectively. This study demonstrated the GAC addition and the electrochemical environment could have a reciprocal influence, leading to more robust syntrophic microbial interactions, which could guide the future application of conductive materials in MEC-AD systems.

2023-07-01·Bioresource Technology

Enhanced methane production in microbial electrolysis cell coupled anaerobic digestion system with MXene accelerants

Article

作者: Ke, Teng ; Yun, Sining ; Liu, Jiayu ; Liu, Lijianan ; Gao, Yangyang ; An, Jinhang ; Wang, Kaijun ; Zhang, Xiaoxue

Accelerants can improve the anaerobic performance of a microbial electrolysis cell coupled anaerobic digestion (MEC-AD). MAX phase titanium aluminum carbide (MAX), multilayer Ti₃C₂T_X MXene (ML-MXene) and few-layer Ti₃C₂T_X MXene (FL-MXene) were utilized as accelerants for MEC-AD to promote CH₄ production and CO₂ reduction at a voltage of 0.6 V. The highest CH₄ yield (358.7 mL/g VS) and the lowest CO₂ yield (57.4 mL/g VS) relative to the control group (170.6 and 125.1 mL/g VS) were obtained in MEC-AD with ML-MXene (0.035 wt%). The digestates of MEC-AD with 0.035 wt% ML-MXene have superior thermal stability (40.9%) and total nutrient content (42.1 g/kg). The ML-MXene enhanced the abundances of Methanosarcina and Methanobacterium. This work highlights the possible role of MXene in promoting methanogenesis. These important findings provide a novel avenue for the development of MXene accelerants for MEC-AD systems.

100 项与 VM-AD 相关的药物交易

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