6533b85dfe1ef96bd12bf175

RESEARCH PRODUCT

Kinetics of nitrogen removal in a MBR nutrient removal activated sludge system

subject

description

The application of membrane bioreactor (MBR) technology to biological nutrient removal (BNR) activated sludge (AS) systems is limited and uncertainty exists as to the impact of the conditions induced by the membranes on the biologically mediated processes of nutrient removal. Two main conditions associated with MBRs are (1) high total suspended solids (TSS) concentrations (8–20 g/L) and (2) different selection pressures due to biomass retention not being based on settleability, compared with conventional systems with secondary settling tanks (SSTs). Recently, Ramphao et al. [1] concluded that incorporating membranes in BNR AS makes a profound difference to the design of the system. Previous investigations on aerobic AS have observed microscopically significant changes in the structure of the flocs and in the ratio between free suspended and aggregated cells, as well as different metabolic activities induced by membrane inclusion [2]. These observations would suggest that the introduction of membranes into BNR systems may cause associated changes in the kinetics of BNR. This will impact on the system performance and hence on the procedures and methods for design and simulation of MBR–BNR systems.