Simulating and predicting the flux change of reverse osmosis membranes over time during wastewater reclamation caused by organic fouling

Abstract

During the operation of the RO system, it's significant to predict the flux change over time. Previous research conducted detailed exploration on the dynamics of RO membrane fouling, and provided a solid database for modelling. In this study, a modified intermediate blocking model with two parameters was proposed to describe the flux change of RO membranes under a huge variety of conditions. Raw data reported by over 20 research groups from 11 different countries was used to validate the feasibility of this model. It proved applicable to describe the flux change of RO membranes fouled by pure organic matter or mixture and tertiary treated wastewater. In order to reveal the relationship between model parameters and foulant concentrations, RO membrane fouling behaviors of typical foulants (sodium alginate (SA), bovine serum albumin (BSA) and mixture) were further investigated. We found that the change of model parameters with SA concentrations was in accordance with Langmuir adsorption isotherm model. Therefore, the model parameters could be calculated by SA concentrations under certain optional conditions, and then the flux change could be predicted by this model. In this way, a novel time-course model was established, which could predict the flux change of RO membranes over time only with SA concentrations. Besides, the synergic effect between SA and BSA on RO membrane fouling was directly quantified.

Keywords: Intermediate blocking model; Membrane fouling; Organic fouling; Reverse osmosis; Time-course model.