A rapid and scalable integrated membrane separation process for purification of polysaccharides from <i>Enteromorpha prolifera</i>

An integrated membrane separation process combining the tubular ceramic microfiltration (MF) membrane and the flat-sheet ultrafiltration (UF) membrane was developed to purify polysaccharides from Enteromorpha prolifera. The effects of membrane pore size, molecular weight cut-off (MWCO), transmembrane pressure (TMP) and adding-water multiples on membrane performance were in-depth studied. The results indicated that the optimal membrane pore size and TMP of the tubular ceramic MF process were found to be 1.2 μm and 0.225 MPa, and the optimal MWCO and TMP of the flat-sheet UF process were found to be 100 kDa and 0.3 MPa. The yields of polysaccharides were increased and optimized while the adding-water multiples was 1 during the diafiltration procedure. Furthermore, the water fluxes could be completely recovered using the specialized membrane cleaning methods, which ensured the reuse of membrane elements and satisfied the demands of industrial production. After purification by this integrated membrane separation process, the content of polysaccharides reached to 96.3%. The purified polysaccharides exhibited the superior moisture absorption and moisture retention properties compared to glycerol, polyethylene glycol (PEG) and luffa water.