Search

Cation exchange resin (CER) has been reported to promote sludge fermentation. However, previous studies have typically focused on the effects of CER on sludge properties to enhance fermentation, and the role of CER as a biocarrier for anaerobic consortia during fermentation has been overlooked. Thus, in this study, the potential of gel-type and macro-reticular type CERs to serve as biocarriers in fermentation was investigated. A significant number of anaerobes appeared to be attached to the surfaces of CER during 2-day fermentation. However, an extended fermentation time negatively affected the attachment of anaerobic consortia, suggesting that CER may be a suitable carrier for short-term fermentation processes, such as biohydrogen fermentation. Electrochemical analyses revealed that the electron transfer capacities of CER with attached anaerobes were enhanced after both 2-day and 28-day fermentation periods, with the macro-reticular type CER exhibiting higher electron transfer capacity than the gel-type CER. Fermentation experiments using mixing model substrates with macro-reticular and gel-type CERs with attached anaerobes showed that the macro-reticular type CER was more beneficial for biohydrogen fermentation than the gel-type CER. Further analyses of microbial communities revealed that hydrogen-producing bacteria (i.e., Caloramator, unclassified_f_Caloramatoraceace, and Sporanaerobacter) were more likely to adhere to the macro-reticular type CERs. This outcome confirmed that macro-reticular type CERs have significant potential as a carrier for anaerobic consortia to promote the generation of hydrogen and volatile fatty acids. These findings are expected to provide a reference for using materials as biocarriers to enhance the biohydrogen fermentation of sludge. [ABSTRACT FROM AUTHOR]

The synthesis of efficient and highly selective catalysts and rational reactor design play decisive roles in the industrial application of the electrocatalytic carbon dioxide reduction reaction (CO 2 RR). In this study, a dual-metal-organic framework (MOF) copper-based catalytic electrode is designed and prepared in one step by in situ synthesis on a foamed copper substrate. The MOF-on-MOF structure can effectively inhibit the generation of H 2 and CO, and further enhance the selectivity of HCOOH. Furthermore, by using cheap and durable poly(tetrafluoroethylene) (PTFE) instead of an expensive and fragile GDE, the optimized reactor design improves the stability and durability of the gas channel and the replaceability of the electrode. The structure-optimized reactor has a maximum Faradaic efficiency of 89.2% in neutral medium, and an average current density of 26.1 mA cm -2 in the flow cell, which has comparable performance to a GDE and can continue to operate stably. The use of PTFE improves the service life of the gas mass transfer channel, and the independent catalytic electrode can provide good catalytic efficiency. These results provide new insights into the reaction mechanism of structurally recombined double MOFs and PTFE-optimized CO 2 RR reactor designs, providing technical support for the practical industrial application of the CO 2 RR., (© 2023 Wiley-VCH GmbH.)