Anaerobic Membrane Bioreactor Treatment of Segregated Bleach Plant Wastewater, 1993 Environmental Conference Proceedings

A pilot scale anaerobic membrane bioreactor (AMB) was utilized to remove adsorbable organic halogen (AOX) from segregated kraft mill bleach plant wastewater. The removal of AOX was evaluated at reactor biomass concentrations of 10,000 and 20,000 mg/L. AOX and ultrafilterable AOX removal efficiencies ranged from 42% to 69% and from 39% to 66% respectively. The amount of influent wastewater AOX that accumulated in the AMB system was not significantly higher than in other anaerobic systems, even with the increased retention of high molecular weight compounds. Accumulation accounted for only 3.5% and 7.4% of influent AOX for the runs at 10,000 mg/L and 20,000 mg/L MLSS concentration, respectively. Even though chlorinated material accumulated to some extent in the system, there was continuous production of methane and no observable decrease in AOX removal efficiency, implying that the biomass did not become inhibited.

The performance of the AMB system was found to be similar to that of a parallel UASB reactor treating the same wastewater. This suggests that an ultrafiltration membrane with a lower molecular weight cut-off would be required to achieve substantial improvement in AMB performance.