Degradation of p-fluoronitrobenzene in biological and bioelectrochemical systems: Differences in kinetics, pathways, and microbial community evolutions

Biodegradation of p -fluoronitrobenzene ( p -FNB) regardless of effective p -FNB removal in a bioelectrochemical system (BES) was achieved for the first time in a biological system (BS). p -FNB degradation showed different kinetics, pathways, and microbial community evolutions in the two systems. About 36   d were required before 100% p -FNB removal in the BS p -FNB , while only 18   d were required in the BES p -FNB . Moreover, the reaction rate constant for p -FNB removal in the BES p -FNB was 1.625   times that in the BS p -FNB . The reduction of nitro groups was the key step for p -FNB removal in the BES p -FNB . However, defluorination was the first step for direct biodegradation of p -FNB in the BS p -FNB . Microbial community analysis showed that the dominant bacteria in the BES p -FNB (20.8% Anaerolineae, 15.9% Flavobacteriia, and 14.8% α-proteobacteria) differed greatly from those in the BS p -FNB (32.8% Flavobacteriia, 24.1% Clostridia and 19.2% Ignavibacteria). In the BS p -FNB , some aerobic microorganisms responsible for direct p -FNB biodegradation were enriched, while p -FA-degrading microorganisms were dominant in the BES p -FNB .