Application of backflushing for fouling reduction during microfiltration of yeast suspensions

The results of microfiltration studies using inorganic TiO2/Al2O3 membranes for solutions containing yeast are reported. The aim of the research was experimental as well as mathematical analysis of the permeate flux dependence on time for cross-flow filtration combined with backflushing using permeate. The effect of operating parameters such as cross-flow velocity, pressure difference across the membrane, and filtration time on permeate flux was experimentally investigated. The transmembrane pressure was changed in the range of 120-320 kPa. The feed was pumped to the membrane module at a cross-flow velocity in the range of 2.73-4.55 m/s. Microfiltration processes were performed at constant temperature (20 degrees C) using feed with constant content of yeast, i.e. 5 10 mg/L. The backflushing runs were performed at constant operating parameters, Delta P-R = 150 kPa; t(R) = 60 s with frequency every 10 min. Experimental results were used for analysis in the frame of mathematical equation obtained using semiempirical models of the filtration and steady-state fluxes.