Patent ID: 8323497

Claim:
A method for removing selenium species from petroleum-contaminated water, the method comprising: (a) establishing a biofilm of selenium-reducing bacteria, under conditions of low petroleum contamination, in a bioreactor having a source of influent water and a port for effluent water, said reactor comprising a plurality of hollow filaments, wherein hydrogen gas is introduced into the lumens of said filaments, said biofilm is formed on the outside of the filaments, and said bacteria in said established biofilm and said hydrogen are effective to reduce selenate and/or selenite in said influent water; (b) iteratively increasing the amount of at least one petroleum contaminant in said influent water, and monitoring said effluent water for selenate reduction to ensure that the bacteria in the biofilm retain the ability to reduce selenium compounds; (c) continuing to contact petroleum-contaminated water with said biofilm, while maintaining in said biofilm selenium-reducing bacteria that grow under such conditions of increased petroleum contamination, and washing non-petroleum-tolerant bacteria away from the biofilm; and (d) separating said effluent water from reduced selenium species.