Effect of solid retention times and vibrational frrequencies on fouling mitigation of submerged vibratory membrane bioreactor
Nur Syafawani Redzwan
Date of Issue2015
School of Civil and Environmental Engineering
This study investigated the optimization of operating parameters by incorporating solid retention times (SRTs) and vibration frequencies for fouling mitigation of a submerged vibratory membrane bioreactor (SVMBR) treating synthetic wastewater. The performance and biomass characteristics were also examined. Over the range of SRT (10 to 200 days), the SVMBR was capable of achieving 97% of total organic carbon removal. The mean sludge particle sizes at different SRTs were in the range of 93.2 – 129.2μm, providing favorable environment for mass interaction. Experiments with prolonged SRT contributed to increasing concentrations of soluble microbial products (SMP) and extracellular polymeric substances (EPS) where EPS concentrations demonstrated an exponential increase, which signified active metabolism of microorganisms. With the aid of vibration, hydrodynamic shear stress was generated within the boundary layer of membrane surface and reduced fouling rate. It was observed that lower vibration frequency prevented mass interaction and caused accelerated attachment of foulants. Results showed that rapid fouling occurred at short SRT and low vibration frequency. Therefore, sufficiently long SRT and high vibration frequency extended membrane life and prolonged SVMBR performance.
Final Year Project (FYP)
Nanyang Technological University