A membrane bioreactor was set up using two pieces of Kubota flat sheet membranes, with nominal pore size of 0.4 ∝m and a total effective area of 0.2 m²atex concentrate processing factory. A steady-state MLSS concentration was attained at 8500 mg/L during biomass acclimatisation. A critical flux of 0.01224 m³/m²h was determined using the flux step method, whereas an optimum operating flux for fouling minimisation was determined from the sub-critical flux region, to be 0.009 m³/m²h at a COD loading of 3500 mg/L. The BOD3 and COD removal efficiencies were 96.78% and 96.99%, respectively.
Keywords: MBR, membrane bioreactors, natural rubber wastewater, critical flux, optimal flux, COD loading, chemical oxygen demand, wastewater treatment, fouling minimisation