An improved model for membrane characterization in forward osmosis

As a promising technology for industrial water recovery, forward osmosis (FO) requires a rigorous and accurate transport model to determine its efficacy for water recovery from challenging effluents, yet current models neglect the non-ideality of concentrated draw solutions, and mass-transfer boundary layers within the process. This work builds upon recent FO transport models and presents an improved FO-based membrane characterization method that addresses the non-ideality of concentrated draw solutions, physical properties that are not based on the bulk draw solution, and all instances of concentration polarization. Using the FO-based characterization method of the present work, consistent water permeability and structural parameter values are obtained with R-2 > 0.985 for multiple inorganic draw solutions. When compared to additional experimental FO transport data, improvements of up to 107% were observed over the existing FO-based characterization method. Using the modeling approach developed in this work, the assessment for a potential FO application is refined by providing the means for accurate process modeling and membrane characterization.