(21c) Integrating Membrane Separations Into the Chemical Engineering Laboratory

Crossflow reverse osmosis (RO) and forward osmosis (FO) systems were constructed to introduce senior-level chemical engineering students to key facets of membrane separations.   During the RO experiments, students examined several commercial RO membranes, measuring water flux and salt rejections at various pressures, flow rates, and feed water salinities.  During FO experiments, students examined a single commercial FO membrane, measuring water flux and feed conductivity at various draw concentrations, flow rates, and temperatures.  Ultimately, students used the data they collected to calculate each membrane’s hydraulic permeability constant and a variable indicative of membrane selectivity (salt rejection for RO and salt permeability for FO).  The data presented is taken directly from the laboratory reports of undergraduate seniors at the University of Connecticut. These data were compared to the manufacturer’s specifications.  Boundary layer theory was utilized in both experiments to predict theoretical permeability and/or flux values after accounting for concentration polarization.  Together, these versatile systems have granted students a thorough understanding of membrane separations and mass transport phenomena in the context of a capstone undergraduate laboratory course.