Roles of polyurethane foam in aerobic moving and fixed bed bioreactors.

The aim of this study was to investigate the performance of sponge as an active mobile carrier for attached-growth biomass in three typical types of aerobic bioreactors to treat a high strength synthetic wastewater. The results show that sponge thickness deteriorated the organic and nutrient removal and 1cm is the optimum thickness for fixed-bed sponge biofilter (SBF). The sponge volume had significant impact on phosphorus removal rather than organic or nitrogen removal, and 20% volume of sponge could achieve 100% T-P removal within 3h in a sponge batch reactor (SBR). When sponge coupled with submerged membrane bioreactor (SMBR), the single system show outstanding ammonium (100% at filtration flux of 10 and 15 L/m(2)h) and phosphorus (> 91% at all fluxes range) removal with optimum pH range of 6-7.