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The aim of this study was to evaluate the potential use of ozonation with pharmaceutical compounds on membrane bioreactor (MBR). The result has shown that high concentrations of pharmaceutical contaminants have caused destruction of cell wall, thereby reducing mixed liquor suspended solids (MLSS). It also resulted in high amounts of biopolymers in the presence of non-biodegradable pharmaceutical compound in MBR. As a result, biological removal decreased and membrane fouling happened. Ozonation treatment reached a chemical Oxygen Demand (COD) removal of 99.9% and caused better effluent quality. The MBR-ozonation process could achieve an acetaminophen and fluoxetine removal of around 98.4 and 57.83%, respectively. [ABSTRACT FROM AUTHOR]

Membranebioreactors (MBRs) are becoming more suitable alternativesfor conventional wastewater treatment devices. The performance ofa pressure-driven MBR is dominantly affected by the hydrodynamic conditionsof the system. This study was conducted to investigate various hydrodynamiccharacteristics including shear stress, cross-flow velocity, and membranefouling resistance, using computational fluid dynamics (CFD). Simulationof two- and three-phase flow for a flat-sheet submerged membrane modulewas carried out, and the results were compared with the experimentaldata. The CFD simulation was implemented to analyze the fluid-flowpattern, shear stress on membrane surfaces, and cross-flow velocitybetween membranes at various mixed liquor suspended solid concentrationsin the bioreactor. It was shown that the cross-flow velocity playsan important role in the membrane fouling and determination of thecritical particle diameter. To achieve an optimal operating condition,the critical particle diameter was calculated at different air flowrates and permeate fluxes. The CFD results showed that the outermostmembranes are more prone to fouling because of the lower shear stresson their surface as well as the lower cross-flow velocity betweenthem and the module wall. Moreover, the effect of the air bubble diameteron the air and liquid shear stress was investigated to determine anoptimal bubble size. [ABSTRACT FROM AUTHOR]

Abstract: This work investigates filtration performance of mesh filter bioreactor for synthetic municipal wastewater treatment. Critical flux is measured by flux stepping method and the effect of aeration rate on the critical flux is investigated. The long term monitoring of trans-filter pressure evolution at sub and super-critical fluxes is performed. The analysis of resistance is achieved by determination of resistances and microscopic observation of bio-cake. Cake resistance values vary from 78% to 92% of total filtration resistance for sub and super-critical fluxes. The effect of variations of specific aeration demands (SADm: 0.5–6m3/m2 h) on suspended solid of effluent, turbidity of filtrate, filtration resistance, and zeta potential of biomass is evaluated. The results show that filtrate quality is decreased when the aeration rate increases. It is attributed to stable formation of dynamic membrane. A rather clear filtrate, less than 18 NTU of turbidity, is obtained for SADm 0.5m3/m2 h. The results also show that the total filtration resistance of the sub-critical flux significantly decreases with increasing aeration intensity until SADm 2m3/m2 h and thereafter slightly decreases. It is also shown that the variations of zeta potential of biomass with aeration rate highly correspond to the alterations of filtration resistance. [Copyright &y& Elsevier]