Studies on performances of membrane, draw solute and modeling of forward osmosis process in desalination - a review

Forward osmosis (FO) is a membrane process that makes use of the osmosis phenomenon for the transport of water from a feed solution to a draw solution across a highly selective membrane under a driving force provided by the osmotic pressure difference between the two solutions. Based on energy consumption, this technology has got an edge over others. However, limited advancement on theoretical modeling for prediction of performance, lack of an ideal FO draw solution, concentration polarization and lack of economic feasibility have made this technology to proceed through further research with an objective of commercialization from 1970 to 2016. Although the technology has many potential applications, like wastewater treatment, membrane bioreactor, oil and gas, pharmaceutical, food and beverage etc., it still faces considerable limitations, including concentration polarization, membrane development and characterization, reverse solute diffusion, development of draw solution and their recovery. In order to address these issues more research is required. This paper presents a state-of-art review on FO technology covering types of membrane, draw solute, their characteristics, concentration polarization, identification of parameters, dynamic modeling of separation, novel membrane and hybrid systems from 103 literatures.