AWWA MTC64608

Minimization of the reverse osmosis (RO) concentrate has become an emerging issue for inland utilities. This study focuses on investigating the innovative low energy usage technology of forward osmosis (FO) to dewater RO concentrate. Several draw solutions are evaluated in this study, including magnetic particles, dendrimers, albumin and sodium chloride. Dendrimers are a promising osmotic media as these macromolecules provide high osmotic pressure and can be reconcentrated using ultrafiltration. With flat-sheet FO configuration, the concentrate from a RO pilot in Rio Rancho, New Mexico, is further concentrated using sodium chloride as the draw solutions. The volume of RO concentrate was reduced by 71%, achieving an overall recovery of 94% combining RO and FO processes. As a proof of concept study, this project summarizes initial feasibility data on the application of FO to minimize the concentrate from RO process. It also contributes to the knowledge of FO process with investigation of innovative draw solutions and high-performance FO membranes. Includes 5 references, tables, figures.