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Methane is a greenhouse gas and significantly contributes to global warming. Methane biofiltration with immobilized methane-oxidizing bacteria (MOB) is an efficient and eco-friendly approach for methane elimination. To achieve high methane elimination capacity (EC), it is necessary to use an exceptional support material to immobilize MOB. The MOB consortium was inoculated in biofilters to continuusly eliminate 1% (v/v) of methane. Results showed that the immobilized MOB cells outperformed than the suspended MOB cells. The biofilter packed with fly ash ceramsite (FAC) held the highest average methane EC of 4.628 g h–1 m–3, which was 33.4% higher than that of the biofilter with the suspended MOB cells. The qPCR revealed that FAC surface presented the highest pmoA gene abundance, which inferred that FAC surface immobilized the most MOB biomass. The XPS and contact angle measurement indicated that the desirable surface elemental composition and stronger surface hydrophilicity of FAC might favor MOB immobilization and accordingly improve methane elimination.

This study aimed to investigate variations of bacterial community and functional characteristics during the continuous thermophilic composting (CTC). Also their differences were discussed when amended with ceramsite and recycled ceramsite as the porous bulking agent. Results showed that the bacterial community shifted greatly and bacterial diversity increased as the CTC proceeded. Firmicutes and Chloroflexi was one of the major phyla at the active and late phase respectively. While Actinobacteria was the dominant phyla during the whole CTC. With the addition of ceramsite and recycled ceramsite, no significant difference was found of the overall bacterial variation trends. But the major phyla of Chloroflexi and Actinobacteria and major genes related to amino acid metabolism and carbohydrate metabolism increased significantly, especially when the recycled ceramsite was added. Redundancy analysis indicated that the succession of bacterial community was tightly related with the pH, water soluble organic carbon, NH4+-N, organic matter and germination index.