A numerical study on the performance prediction of forward osmosis process

Abstract

The performance of FO is predicted numerically by one-dimensional model. Mass balance equation for the feed and draw side are coupled with the water flux model considering concentration polarization. Results of the present study showed the flow rate of the feed and draw solution should be determined by considering the water flux and the water recovery efficiency. Using the draw solution of as high concentration as possible is helpful to improve the water flux. As increasing the membrane module length, the averaged water flux per membrane length decreases but the water production increases. Therefore, in order to determine the membrane length, it is required to consider the water flux reduction, total water production, membrane size and the number of membrane. The water flux of counter-current flow is about 10% higher than that of co-current flow. Forming feed solution into series and draw solution into rows are effective in increasing water flux.