Reduced sludge production in a membrane bioreactor by uncoupling metabolism and its effect on phosphorus accumulation in the biomass.

Unlabelled: Due to its limited recycling or reuse, treatment and disposal of excess waste activated sludge has been a major challenge. As a preemptive method, therefore, uncoupling metabolism for reduced sludge production has been investigated recently. In this study, we operated a pilot-scale AO-membrane bioreactor (MBR) system incorporating an anaerobic sludge holding tank (SHT) in a sludge recycling line to induce uncoupling metabolism, and investigated sludge production and treatment efficiency.

Analysis of extracellular polymeric substance (EPS) release in anaerobic sludge holding tank and its effects on membrane fouling in a membrane bioreactor (MBR).

Amongst sludge reduction strategies, the anaerobic side-stream sludge holding tank (SHT) is of particular interest because it has shown significant sludge reduction efficiency. However, due to the anaerobic and starving environment of the SHT, the release of extracellular polymeric substance (EPS) may be stimulated, and it may hamper the application of the SHT to the membrane bioreactor. In order to investigate the effect of sludge storage on EPS release, sludge samples from a pilot-scale sequencing batch reactor coupled with SHT was incubated in a series of bench-scale SHT reactors for different periods of time (0-24 h).

Evaluation of WAS reduction efficiency using kinetic parameters in pilot-scale SBR operated with anaerobic sludge holding tank.

By evaluating microbial kinetic parameters of a pilot sludge blanket reactor (SBR) plant operated with an anaerobic sludge holding tank (SHT), it was found that the sludge production was reduced by 63.5%. According to the theory of uncoupling metabolism, the microorganisms were induced to the initial stage of the endogenous phase in SHT, which resulted in the reduction of yield coefficient.