Fast start-up and stable performance coupled to sulfate reduction in the nitrobenzene bio-reduction system and its microbial community

► Sulfate reduction speeds up the start-up of nitrobenzene (NB) treating system. ► NB removal is attributed to the bio-reduction and co-metabolism. ► NB reduction is coupled to the on-going sulfate reducing process. ► Microbial community strongly affects NB reduction and system performance.