Forward osmosis desalination by utilizing chlorhexidine gluconate based mouthwash as a reusable draw solute

Abstract

Forward osmosis is a membrane technology which is of high interest for water reclamation and desalination. To stabilize the forward osmosis (FO) process practical and cost-effective, selection of an appropriate draw solute is essential. Chlorhexidine gluconate based mouth-wash (CMW) has been determined to have high osmolality and low toxicity, rendering it applicable as a novel draw solute in future applications. The experimental data of the FO process demonstrated the advantage of using CMW compared with using conventional salt (NaCl), and parameters such as the water flux (Jw), reverse salt flux (Js), and specific reverse salt flux (Js/Jw) were considered. The specific reverse salt flux (Js/Jw) of 100% mouthwash was found to be 0.07g/L, lower than that of 0.5M NaCl. A thermally driven membrane distillation (MD) was used for the recovery system. Furthermore, the reusability of the draw solute was determined to be an effective agent for antifungal and antimicrobial activity. Hence, the overall performance supported CMW as a promising draw solute for FO-MD systems.