Corrected normalized permeate flux for a statistics-based fouling detection method in seawater reverse osmosis process

AbstractIn the real-field application, the operation conditions for seawater reverse osmosis (SWRO) processes such as pressure, temperature, recovery rate, and feed concentration vary, which changes the permeate flow rate with no fouling. In order to detect fouling from the fluctuating permeate flow rates due to various operation conditions, they should be normalized. However, the normalization method using ASTM D4516 method still produces the fluctuation in the normalized permeate flow due to poor selections of osmotic pressure and temperature correction factor (TCF) equations, which do not reflect the characteristics of feed water and reverse osmosis membrane in the field very well. This work introduces the corrected normalized permeate flux (NPF) using the fitted osmotic pressure and TCF equations to minimize the fluctuation during a non-fouling situation and suggests a statistical approach to detect fouling by comparing the mean values of two groups with different variances. The laboratory-scale SWRO ...