Modern Opportunities of Forward Osmosis Are Considered,with Five Key Challenges

The modern opportunities of forward osmosis are considered, with five key challenges faced by FO systematically reviewed and discussed. These are concentration polarisation, membrane fouling, reverse solute diffusion, and the need for new membrane development and draw solute design in FO. The intrinsic relationships between these five challenges are explored. Recently, forward osmosis (FO) has attracted growing attention in many potential applications such as power generation, desalination, wastewater treatment, and food processing. However, there are still several critical challenges, which are the focus of current research: Concentration polarisation, membrane fouling, reverse solute diffusion, and the need for new membrane development and draw solute design in FO. This paper – by scientists at the University of South Australia and at Nanyang Technological University in Singapore – reviews recent developments in FO, focusing on the opportunities and challenges. It begins by discussing the advantages of the FO process over pressure-driven membrane processes. These potential advantages lie in FO's low energy consumption, low fouling propensity, reduced or easy cleaning, low costs, high salt rejection, and high water flux. Next, the recent applications of FO – including power generation, seawater/brackish water desalination, wastewater treatment, and food processing – are described in terms of these advantages. The key part of this review is a detailed discussion of the five critical challenges faced by FO and their relationships: Concentration polarisation, membrane fouling, reverse solute diffusion, and the need for membrane development and the design of the draw solute. Source: workingwithwater.filtsep.com