Fabrication of forward osmosis membrane using nata-de-coco as raw materials for desalination

Liza Bautista-Patacsil, Mayzonee V. Ligaray, John Paulo C. Sayao, and Joule Renniel F. Belosillo, Malayan Colleges Laguna

 Ramon Christian P. Eusebio

Department of Chemical Engineering, University of the Philippines Los Baños 

Aileen H. Orbecido

Department of Chemical Engineering, De la Salle University 

Arnel B. Beltran

Department of Chemical Engineering, De la Salle University 

Abstract- A Forward Osmosis (FO) membrane was fabricated using a locally available material nata de coco (NDC) to form a bacterial cellulose (BC) film. Sodium alginate was used to form composites with the BC film. Two concentrations (10% and 15%) of cross-linking agent, CaCl2, were compared in terms of its performance as a FO membrane for application in desalination. Two salts were compared as draw solution: 2M sucrose (C12H22O11) and 2M magnesium chloride (MgCl2). The performance of the fabricated NDC-FO membrane was investigated in terms of water flux, salt flux and percent salt rejection in a laboratory-scale FO system. The 15% CaCl2 solution was observed to give high water flux, low salt flux, and high salt rejection compared to the 10% CaCl2. The 15% CaCl2 solution produced a more tensile membrane compared to 10% CaCl2, one endures pressure at the suction points of the FO module while the other breaks after some time of operation, respectively. The NDC-FO membrane has an average contact angle of 14.137° with an average thickness of 0.159 mm. The 2M MgCl2 performs better than sucrose as a draw solution. The commercial Cellulose Tri-Acetate (CTA) FO membrane was used to benchmark the performance of NDC-FO membrane. The NDC-FO membrane produces a water flux of 4.01 LMH with 88.39% salt rejection, which is comparable to the water flux of CTA with 7.97 LMH and 100% salt rejection. Results showed the potential of nata de coco as raw material for FO membrane. © 2020.

Keywords – Desalination, Forward Osmosis, Nata de coco

Citation – Bautista-Patacsil, L, Ligaray, M.V., Sayao, P.C., Belosillo, R.F., Eusebio, R.C.P. Orbecido, A.H., Beltran, A.B. Fabrication of forward osmosis membrane using nata-de-coco as raw materials for desalination. Taiwan Water Conservancy, Vol. 68, Issue 1, March 2020, Pages 36-43.

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