DECARBONIZATION EFFICIENCY AND MICROBIAL COMMUNITY STRUCTURE IN BIOMETHANATION USING ANMBR

Abstract

 As CO₂ emission reduction and resource recovery have become common challenges globally, biomethanation technology is regarded as one potential solution. In biomethanation reactors, although the diversity and interactions of microorganisms are complex, their variations significantly impact fermentation efficiency which requires quantitative analysis. This study conducted a long-term continuous experiment in a 15L AnMBR (anaerobic membrane bioreactor) to evaluate the changes in decarbonization efficiency and microbial community structure under different carbon loading. The results showed that at a carbon loading rate of 1.0 g-C/L/d, the decarbonization rate reached over 85%. When carbon loading increased, the dominant microbial species in the reactor shifted from the methane-producing archaeon Meth-anosarcina (17.7%) to the hydrogenotrophic methanogen Methanobacterium (39.4%), which led to a high CH₄ production rate (67 mL/gVSS/h). It was indicated that utilizing a filtration membrane for solid-liquid separation can maintain a high concentration of methanogenic archaea and improve the reactor's decarbonization efficiency and CH₄ production.