Evaluation of Renewable Gluconate Salts as Draw Solutes in Forward Osmosis Process

摘要

Draw solution is one important factor to determine the separation performance in forward osmosis (FO) process. However, most draw solutions face severe reverse solute leakage and energy-intensive recovery problems, which lead to a significant performance decline. Exploration of renewable natural compounds as draw solutes may effectively break out the predicament of most current draw solution. In this work, a series of renewable, no-toxic gluconate salts are systematically investigated as draw solutes for FO applications. Their physicochemical properties are investigated systematically and related to the FO performance. The result shows that 2 M Glu-K draw solution may generate a comparable water flux (～23.17 LMH) to that of NaCl solution, but with a significantly lower solute leakage (～1.09 gMH), with DI water as the feed solution under PRO mode. Glu-K draw solution is further applied for juice reconcentration with a reasonable good performance achieved. Draw solution recovery by nanofiltration (NF) is also performed. This study provides useful information on using natural draw solutes in the FO process and facilitates its practical applications in the food processing field.