Modelling the maintenance of membranes in reverse-osmosis desalination
Résumé
Biofouling of membranes, amplified by recurring algal blooms, significantly reduces the efficiency of reverse-osmosis desalination. Degradation or wear of membranes caused by biofouling manifests as a loss in pressure, and maintenance is required otherwise membranes will fail. In this research, we model membrane wear and maintenance in a novel way, describing the hidden states through time of individual membrane elements in a reverse-osmosis pressure-vessel. Our mathematical model provides the basis for a simulation platform. We estimate parameters of the model using statistical methods, among them the particle filter. Maintenance planning is interesting because membrane elements can be replaced or swapped or cascaded or cleaned, and these differing interventions have different restorative effects. We demonstrate the potential for our model to support decision-making for maintenance planning and to reduce maintenance costs.