Polymeric membrane fouling in sugarcane juice ultrafiltration: role of juice polysaccharides

In the present work, the role of sugarcane juice polysaccharides in the fouling of polymeric polysulphone (PS) and polyethersulphone (PES) membranes was investigated. The polysaccharide fraction was isolated by ethanol precipitation; commercial membranes in the 30–100 kD nominal molecular weight cut-off (MWCO) range were investigated in the static (adsorption) and the dynamic (ultrafiltration) modes. Size exclusion chromatography of the polysaccharide fraction showed a high molecular weight (HMW) component with ∼130 kD and a low molecular weight (LMW) component in the range of 1 kD. Though a significant amount of the fraction was retained by the membranes in the dynamic mode of operation, some adsorption under static conditions was also observed. Fouling resulted in a shift in the MWCO of the membranes to lower values. Further analysis using UV spectroscopy and BCA microassay indicated the HMW fraction to contain protein moieties that adsorbed on the membrane.