Assessment of the Design Parameters for Wastewater Treatment by Reverse Osmosis

A modelling procedure is presented to predict the fluxes and solute concentrations in different flows for reverse osmosis (RO) spiral-wound modules. Important underlying factors for this procedure are the osmotic pressure for various solutions, the hydrodynamic flow profile in the concentrate channel, and the intrinsic separation characteristics of the membrane material. Experiments were carried out using a flat sheet test cell to determine the parameters of the mass transport model. Results of residence time distribution (RTD)-measurements on an industrial spiral-wound module were used to determine macroscopic fluid flow regimes resulting in the definition of dead volume fraction, average residence time and Pe-number. The evaluation of the modelling procedure has been based on experimental data of an industrial membrane plant system.