Teaching Mass Transfer and Filtration Using Crossflow Reverse Osmosis and Nanofiltration: An Experiment for the Undergraduate Unit Operations Lab
A crossflow reverse osmosis (RO) system was built for a senior-level chemical engineering unit operations laboratory course. Intended to teach students mass transfer fundamentals related to membrane separations, students tested several commercial desalination membranes, measuring water flux and salt rejections at various pressures, flow rates, and feed water salinities. Ultimately, students used the data they collected to calculate each membrane’s hydraulic permeability constant and salt rejection. These values were compared to the manufacturer’s specifications. Boundary layer theory was utilized to predict theoretical permeability, flux values, or rejection for saline feeds after accounting for concentration polarization. This system has also shown versatility, being used as part of an undergraduate/graduate level Membrane Separations course and to demonstrate RO to visiting high school students.