Ni-PVDF中空纤维膜阴极促进微生物电合成产甲烷

Ni-PVDF hollow fiber membrane cathode for promoting microbial electrosynthetic methane production

微生物电解池可以利用含产甲烷菌的生物阴极还原CO_(2)产甲烷。通过化学镀镍法制备导电的镍基聚偏氟乙烯(Ni-PVDF)中空纤维膜,将Ni-PVDF中空纤维膜组装为膜组件电极,充当微生物电合成系统阴极。阴极镍层催化的析氢反应产生的H_(2)与CO_(2)被氢营养型产甲烷菌利用,并通过间接电子传递生产甲烷。结果表明,系统运行稳定之后,Ni-PVDF中空纤维膜组件阴极的CO_(2)直接传输系统的累积甲烷产量(2176.24 mmol/(L·m 2))远大于该膜组件仅作为阴极的CO_(2)间接传输系统的累积甲烷产量(613.94 mmol/(L·m 2))。膜组件阴极的高比表面积以及膜组件阴极直接CO_(2)传输降低了气液传质阻力,确保了直接CO_(2)传输系统的高甲烷产量。

Microbial electrolysis cell can utilize biocathode attached to methanogens to reduce CO_(2) to methane.A conductive nickel-based polyvinylidene fluoride(Ni-PVDF)composite hollow fiber membrane was prepared by electroless nickel plating.The Ni-PVDF hollow fiber membrane was assembled into a membrane module electrode,which served as the biocathode of the microbial electrolysis cell for methane production.The H_(2) produced by the hydrogen evolution reaction catalyzed by the cathode nickel layer and CO_(2) were utilized by the hydrogenotrophic methanogens to produce methane through indirect electron transfer.The results showed that the cumulative methane production(2176.24 mmol/(L·m^(2)))of the direct CO_(2) transport system using the Ni-PVDF hollow fiber membrane module cathode was much greater than that of the indirect CO_(2) transport system with the membrane module only acting as the cathode(613.94 mmol/(L·m^(2)))after the system run stably.The high specific surface area of the membrane module cathode and the direct CO_(2) transmission of the cathode greatly reduce the gas-liquid mass transfer resistance,thus ensuring the high methane production of the direct CO_(2) transmission system.