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°C) using feed with constant content of yeast, i.e. 510 mg/L. The backflushing runs were performed at constant operating parameters, ▵PR=150 kPa; tR=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.