This study tests a hydrogen-based membrane biofilm reactor (MBfR) to investigate simultaneous bioreduction of selected oxidized contaminants, including nitrate (-N), sulfate (), bromate (), chromate (Cr(VI)) and para-chloronitrobenzene (p-CNB). The experiments demonstrate that MBfR can achieve high performance for contaminants bioreduction to harmless or immobile forms in 240 days, with a maximum reduction fluxes of 0.901 g -N/m2·d, 1.573 g /m2·d, 0.009 g /m2·d, 0.022 g Cr(VI)/m2·d, and 0.043 g p-CNB/m2·d. Increasing H2 pressure and decreasing influent surface loading enhanced removal efficiency of the reactor. Flux analysis indicates that nitrate and sulfate reductions competed more strongly than , Cr(VI) and p-CNB reduction. The average H2 utilization rate, H2 flux, and H2 utilization efficiency of the reactor were 0.026 to 0.052 mg H2/cm3·d, 0.024 to 0.046 mg H2/cm2·d, and 97.5% to 99.3% (nearly 100%). Results show the hydrogen-based MBfR may be suitable for removing multiple oxidized contaminants in drinking water or groundwater.

A sequencing fed biofilm batch reactor (SFBFBR) seeded with returning activated sludge of a WWTP was started up to enrich Anammox (Anaerobic Ammonium Oxidation) bacteria and to investigate the nitrogen removal characterization of the Anammox biofilm system. Initially, the operation period was controlled at 3 days and the mineral medium (30 mg/l ammonium, 30 mg/l nitrite, about 2 L) was supplied continuously to SFBFBR in the first 68 hours. After 44 days’ cultivation, ammonium and nitrite concentration were decreased simultaneously without COD and DO, which means the anammox activity presented in the reactor. From t=55 days, in order to further enrich anammox bacteria, the substrate load began to increase by reducing the operation period from 3 days to 1 day and increasing the ammonium and nitrite concentrations. At the end of the experiment, the reactor was able to treat nitrogen loading rates up to 200±10 mg N/(L.d). The ammonium and nitrite reacted in the stoichiometrical of 1:1.135.