Abstract
Hybrid desalination systems combining both thermal and membrane desalination processes are currently considered a viable alternative to conventional desalination plants. Recently, an incorporation of forward osmosis (FO) with membrane distillation (MD) has been considered as a new hybrid desalination technology. Nevertheless, few works have been done to design and optimize these types of new hybrid systems. The focus of this study was to investigate FO–MD hybrid process in which MD is being used to recover draw solutes in product water from FO. Laboratory-scale systems for FO and MD were developed to examine the effect of key operating conditions (draw solute concentration, operation time, temperature, etc.) on flux and solute transport. The results indicated that the efficiency of FO–MD hybrid is affected by the selectivity of draw solute transport through the MD membrane. As decreasing the temperature difference between the feed and distillate in MD, the rate of separation decreases but the selectivity increases. Based on these results, a simple model was proposed to analyze the efficiency of this FO–MD hybrid system.
Acknowledgments
This research was supported by a grant (code# C106A152000106A085700220) from Plant Technology Advancement Program funded by Ministry of Construction and Transportation of Korean government and the National Research Foundation of Korea Grant funded by the Korean Government (MEST) (NRF-2010-0029061).
Notes
7th Aseanian Membrane Society Conference (AMS7), 4–7 July 2012, Busan, Korea