FOULING OF A CERAMIC MICROFILTRATION MEMBRANE BY CORN STARCH HYDROLYSATE

The effect of operating parameters on fouling of a ceramic microfiltra tion membrane by corn starch hydrolysate of 95 dextrose equivalence wa s studied. Transmembrane pressures above 100 kPa had Little or no effe ct on flux. Cross-flow velocity had a significant beneficial effect. T he rate of flux decline was reduced significantly when the feed was ad justed from its natural pH of 4.2 to 10. However, this resulted in a d ark brown clarified syrup (permeate). Scanning electron microscopy sho wed extensive fouling layers on the alumina surface with conventionall y processed dextrose solutions and the least fouling layer with corn s tarch hydrolysate adjusted to pH 10. Maximum steady state Aux for unco ncentrated hydrolysate at its natural pH was 178 LMH obtained at low t ransmembrane pressures (103 kPa, 15 psi) and high cross-flow Velocitie s (5 m s(-1)). Adjustment of the pH to 10 can increase the flux by 40% .