Abstract:A continuous stirred hydrogen-based membrane biofilm reactor (CS-MBfR) was used to investigate the effects of the H2 pressure and the influent concentrations of NO3-, SO42- and SeO42- on the removal of SeO42- from aqueous solution. As the experiment results showed, H2 pressure was a key factor influencing the removal of NO3-, SO42- and SeO42-. With the increase of H2pressure from 0.02MPa to 0.08MPa, the removal rates of SO42- and total Se increased from 3.5% and 60.7% to 46.3% and 2.1%, respectively, while NO3- was completely reduced to N2 throughout the process. When influent NO3- concentration increased from 5 to 50mg/L, the removal rates of SO42- and SeO42- gradually decreased to 0, and the NO2- accumulation was observed. The removal of NO3- and SeO42- was not affected by increasing influent SO42- concentration, and their removal rates were above 99.5% and 65%, respectively. The priority sequence of electron accepting ability is NO3->SeO42->SO42-. Under the conditions of H2 pressure 0.04MPa, NO3- 10mg/L, SO42- 25mg/L, and Se (VI) 0.25~2mg/L, the removal rate of total Se was above 80%.