Desalination, Vol.448, 87-92, 2018
Evaluation of food additive sodium phytate as a novel draw solute for forward osmosis
Proper draw solution is a crucial factor to generate a high performance in FO process. In this study, a phytic acid and its salt (PA-Na) were evaluated as novel draw solutes in FO process. The effects of the solution pH and concentration on the physicochemical properties were investigated systematically. Using 0.45 M PA-Na draw solution (pH = 7) and DI water feed solution, a relative high water flux of 19.02 LMH and a low solute flux of 0.51 gMH can be obtained, with HTI-TFC membrane in the PRO mode. An even better performance of a 30.35 LMH water flux and a 0.61 gMH solute flux can be achieved using the self-made HPAN-TFC membrane. The comparison of PA-Na and NaCl draw solutions shows that PA-Na draw solution has a much lower draw solute leakage and a competitive water flux. In addition, the application of PA-Na draw solution for the brackish water desalination was explored. The diluted PA-Na draw solution after FO may be used directly in food production by further dilution. In general, the non-toxicity and satisfactory FO performance of this food additive demonstrate its great potential as a draw solute for FO applications.