Biofouling mechanism of polysaccharide-protein-humic acid mixtures on polyvinylidene fluoride microfiltration membranes

摘要

The biofouling mechanism of organic mixtures on porous polyvinylidene fluoride membranes was tested to determine how to examine the fouling potential of a membrane for water treatments with more representative feed compositions including protein, polysaccharides, and natural organic matters. The three-dimensional structure and compositions of the fouling layers were examined using confocal laser scanning microscopy and the filtration resistances of the fouled membranes were estimated. The filtration resistance analyses demonstrated that feeds with a single-component foulant will cause serious clogging in the pores and form a looser fouling layer structure on the membrane; however, a mixed composition resulted in less clogging in the pore and a denser layer structure on the membrane because of over deposition and interactions among the foulants. The fouling potential of a membrane examined with a single-component will result in an under-estimation of the filtration resistance of the fouling layer and an over-estimation of irreversible fouling. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.