EPS and SMP dynamics at different heights of a submerged anaerobicmembrane bioreactor (SAMBR).

Abstract

Membrane bioreactors (MBR) technology for wastewater offers many advantages over conventional tech-nologies such as high effluent quality, less footprint and others. The main disadvantage of membranebioreactors (MBR) is related to membrane fouling, which is mainly caused by extracellular polymericsubstance (EPS) and soluble microbial products (SMP). This research studied EPS and SMP dynamics atdifferent heights of a submerged anaerobic membrane bioreactor (SAMBR). The SAMBR was operatedunder two organic loading rates (OLR) (0.79 and 1.56 kg/m3d) and was fed with synthetic wastewaterwith glucose as the carbon source. The results showed percentages of chemical oxygen demand (COD)removal above 95% and the highest COD removal rates were observed at the bottom of the reactor (>83%)for both OLR. The EPS showed a stratification with highest quantities in the supernatant. For the SMP thehighest concentration was in the bottom of SAMBR where utilization predominated associated productswhereas in the SAMBR supernatant predominated biomass associated products. The OLR change led to asignificant increase in SMP accumulation but not in EPS. These facts showed that EPS and SMP dynamicin the SAMBR seemed to be mainly influenced by biological activity, total suspended solids concentrationand substrate composition.