Forward osmosis: Principles, applications, and recent developments

Abstract Consumer demand for the highest quality concentrated products with natural flavor and taste, free from chemical additives and preservatives, has triggered the development of novel membrane-based processes for the concentration of liquid foods. Forward osmosis is one such alternative. The increase in scientific reports in the literature demonstrates the various emerging applications of this technology in food processing, desalination, and pharmaceuticals. The most vital capability of forward osmosis is concentration of liquid foods at ambient temperature and pressure without major fouling of the membrane. Low energy consumption, low fouling propensity, reduced or easy cleaning, low cost, high salt rejection, and high water flux are some of the advantages of forward osmosis over other membrane processes. The current limitations of forward osmosis are concentration polarization, fouling of the membrane, back diffusion of draw solute, and the design/fabrication complexities of suitable membranes. This chapter discusses the current advances in forward osmosis and focuses on the opportunities and challenges associated with this technology.