Biological autocrine signaling molecule enhanced synchronously removal of gaseous n-hexane and dichloromethane in a biotrickling filter: Performance and mechanisms.

Biological waste gas treatments are promising approaches for the sustainable development of the petrochemical industry, which was limited by low removal efficiency and prolonged start-up due to difficulties in biodegradation and biofilm formation. Based on the independently developed biological autocrine signaling molecule (SMH13), this study explored its performance and mechanisms on enhancing synchronously removal of n-hexane and dichloromethane. The quorum sensing (QS) of the n-hexane-degrading strain Pseudomonas sp. HY-6 was activated, and the concentration threshold to fully activate the QS was 500 µg·L-1. The extracellular polymeric substance (EPS) secretion and cellular surface hydrophobicity were promoted by 20 % and 40 % with SMH13, which were benefit to the biofilm formation and its n-hexane utilization. The start-up period of a lab-scale biotrickling filter (BTF) treating n-hexane and dichloromethane mixed waste gas was shortened from 19 days to 13 days with 23 % improvements on elimination capacity. The enrichment of alkane-degrading genera (Mycobacterium) and halogenated hydrocarbon-degrading genera (Chujaibacter, etc.) was positively correlated. The synchronously enhanced removal of n-hexane and dichloromethane was achieved through promoting the cell proliferation, EPS secretion, biofilm formation, and functional genera enrichment by activating QS using SMH13.