A NOVEL BIOFILM-MEMBRANE REACTOR FOR AMMONIA OXIDATION AT LOW CONCENTRATIONS

For the oxidation of low concentrations of NH4+-N, conventional biofil m reactors such as a rotating biological contactor encounter difficult y due to mass transport limitation of NH4+-N. Therefore, the authors h ave developed a novel biofilm-membrane reactor, in which biomass is fi xed on the surface of rotating membrane disks to enhance NH4+-N transp ort into the biofilm. Three long-term bench-scale experiments were car ried out and sufficient nitrification efficiency was obtained even at low levels of NH4+-N. The experimental results were evaluated in compa rison with model simulation. (C) 1997 IAWQ. Published by Elsevier Scie nce Ltd.