FORWARD OSMOSIS PROCESS FOR SECONDARY EFFLUENT AND SEAWATER APPLICATION.

Abstract

The purpose of this research was to investigate the feasibility of cellulose tri-acetate (CTA) based Forward Osmosis (FO) membrane for seawater desalination applications and evaluate the FO membrane fouling behaviour with secondary effluent under different organics concentration. Secondary effluents with low organic concentration (10-50 ppm TOC) and high organic concentration range (100 and 200 ppm TOC), were investigated to understand the fouling propensity of the FO membrane. One of the key contributions of this study is the development of a cake formation model for the organic fouling of FO membrane. In addition, typical cleaning methodology and flux recovered after cleaning has been determined comprehensively. Furthermore, this study involved testing the feasibility of FO - nanofiltration (NF) synergistic system for desalination of actual seawater for the production of potable/drinking water. The integration of FO and NF process was able to produce potable water with TDS less than 500 ppm and boron concentration lower than 2.4 ppm, conforming to the drinking water guideline. Hence, this study concluded that the FO-NF process could be employed efficiently for seawater desalination.