Cleaning optimisation of reverse osmosis membranes used for wastewater reclamation

Wastewater reclamation contributes to the preservation of conventional water resources and thus helps to ensure appropriate human development for future generations. Wastewater reclamation can be achieved through several technologies. One of the most common technologies is the tertiary treatment of urban municipal wastewater, which is often based on membrane technologies. Reverse osmosis is an effective separation technology for removing dissolved salts and low molecular weight organic compounds. However, membranes suffer from fouling, which directly reduces technical, environmental and economic feasibility of the process and hence of the reclamation plant. One of the strategies helpful to reduce fouling is the optimisation of the membranes' cleaning and maintenance. The aim of this work is to test the impact of the membrane cleaning protocol design on the recovery of the original properties of a reverse osmosis membrane used for several years in a wastewater reclamation plant in Spain. Furthermore, the work is focused on the validation of the adequacy of the most-common indicators used for assessing membranes' cleaning efficiency.