Desalinating microalgal-rich water via thermoresponsive membrane distillation. Issue 5 (October 2021)

• Record Type: Journal Article
• Authors: Lyly, L.H.T.; Ooi, B.S.; Lim, W.J.; Chang, Y.S.; Derek, C.J.C.; Lim, J.K.
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 5(2021)
• Publication Date: 2021-10
• Subjects: Thermoresponsive -- Composite membrane -- Underwater contact angle -- Thermal cleaning -- Microalgal fouling; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105897
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this study, composite membranes for direct contact membrane distillation (DCMD) were fabricated by casting a top layer of PVDF that has blended with different dosages of thermoresponsive particles onto PTFE support. The fabricated composite membrane exhibits thermal-cleaning properties using pure water as a cleaning agent. The surface property and thermoresponsiveness of composite membranes were tested underwater at both room and elevated temperature (60 °C). The fouling tendency and cleaning efficiencies of composite membranes were evaluated using model foulants namely bovine serum albumin (BSA) and sodium alginate (SA). Membranes dosed in with poly(N-isopropylacrylamide) (PNIPAM) showed both hydrophobic and oleophobic properties under elevated temperature (60 °C). This makes it suitable to be used for membrane distillation (MD) operation. It was found that composite membranes with 1.0% PNIPAM showed excellent cleaning efficiency with flux recovery of 88.26% after microalgae fouling. Hence, the swelling and shrinking of PNIPAM in composite membrane that create surface actuation force during membrane thermal cleaning was able to repel the algal organic matter (AOM) that fouled on membrane surface. Besides, the rehydrated PNIPAM could repel the foulants that interacted with hydrophobic interaction during cold water washing. Graphical Abstract: ga1 Highlights: Membrane dosed with PNIPAM particles exhibits thermoresponsive properties. Thermal cleaning of composite membrane was tested at alternate temperature. Omniphobic properties of membranes under elevated temperature were observed. Thermoresponsive membrane showed significant flux recovery after microalgae fouling. Effective in cleaning algae organic matters interacted via hydrophobic interactions.