An alginate active layer of polyether sulfone membrane suppresses algae-fouling in repeated filtration of Chlorella vulgaris for a higher recovery of water permeation flux

Abstract

Interfacial polymerization was used to make a composite membrane between alginate and trimesoyl chloride (TMC) on the surface of a polyether sulfone (PES) support membrane, which was defined as an alginate-coated polyether sulfone composite membrane (A/PES membrane). Scanning electron microscopy and atomic force microscopy were used to observe the morphological structure of the membrane. The membrane surfaces were smooth and achieved a hydrophilic character after formation of an alginate active layer. The A/PES membrane had a higher water permeability than the commercial PES ultrafiltration membrane (30 kDa) during microalgae filtration after 200 min of filtration. Backwashing can recover the water permeability of the A/PES membrane and remove Chlorella vulgaris cells adsorbed on the membrane surface. The alginate-coated polyether sulfone composite membrane efficiently suppressed algae-fouling, and the rejection of Chlorella vulgaris cells was over 99.9%.