Tailoring the surface properties of carbon nitride incorporated thin film nanocomposite membrane for forward osmosis desalination. (February 2020)

• Record Type: Journal Article
• Authors: Aziz, A. Abdul; Wong, K.C.; Goh, P.S.; Ismail, A.F.; Azelee, I. Wan
• Is Part Of: Journal of water process engineering. Volume 33(2020)
• Publication Date: 2020-02
• Subjects: Carbon nitride -- Reverse osmosis -- Forward osmosis -- Thin film nanocomposite; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2019.101005
• Languages: English
• ISSNs: 2214-7144

Abstract

Graphical abstract: Highlights: CN and pCN were incorporated into the substrate and PA layer of FO membrane. CN and pCN increased the membrane surface charge, roughness and hydrophilicity. pCN-pCN-TFN and CN-pCN-TFN showed water flux 40% and 65% higher than TFC membrane. pCN in the substrate has successfully reduced the ICP. Abstract: Thin film nanocomposite (TFN) membranes incorporated with carbon nitride (CN) or protonated CN (pCN) were fabricated for forward osmosis (FO) desalination. The CN and pCN were incorporated within the polyamide (PA) layer which was supported by pCN incorporated polysulfone (PSf) substrate to form the TFN membrane. It was found that the presence of pCN in the substrate has favourably altered the intrinsic properties and affected the formation of PA layer. The physico-chemical characterizations indicated that the presence of both CN and pCN enhanced the surface hydrophilicity but reduced the surface negativity of the PA layer. These features have resulted in the improved water transport and salt rejective ability. As a result, CN-pCN-TFN membranes exhibited improved water permeability by about 70% (0.67 L/m 2 h bar) compared to TFC membrane while maintaining salt rejection of 94.5%. CN-pCN-TFN also exhibited better anti-fouling property compared to TFC in which the flux decline was only half of that of TFC membrane during the 9 -h antifouling test. This work demonstrates the feasibility of using functional CN and pCN to independently tailor the substrate and PA layer properties of the TFN membrane, hence improving the desalination performances of the membrane.