Research progress on characteization of concentration polarization and membrane fouling of forward osmosis
Forward osmosis (FO), a novel membrane separation technology with low energy consumption and high water recovery, has been drawn attention around the world.Its driving force for separation is natural pressure difference existing between the feed solution and draw solution.Concentration polarization and membrane fouling are two main factors resulting in decrease in water flux.Increase in cross-flow velocity would significantly reduce negative influence of external concentration polarization on FO performance.Internal concentration polarization could only be reduced through improvement on membrane structure and membrane performance.Membrane fouling is one of the technical barriers of FO.Mechanism of membrane fouling includes adsorption on membrane surface and cake layer (gel layer) formation.Membrane foulants include dissolved inorganic matter, colloid and suspended matter, organic matter, and microorganisms.Properties of FO membrane and feed solution, membrane orientation, and operating conditions are the affecting factors of membrane fouling.The methods for fouling control include pretreatment,hydraulic methods, cleaning, and modification of membrane structure, etc.Research on mechanisms of membrane fouling and its control methods can promote the development and application of FO technology.
NETL
NSTL
万方数据
维普
