A design method of the RO system in reverse osmosis brackish water desalination plants (calculations and simulations)

This paper proposes a simple design method of the RO system in RO brackish water desalination plants. This method is based on the application of maximum available recovery without scaling of any of the compounds present in the water as silica, calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate, and calcium fluoride, and membrane manufacturer design guidelines, and the plant production. It is a continuation of the paper "A design method of the RO system in reverse osmosis brackish water desalination plants (procedure)" presented at the conference on Membranes in Drinking and Industrial Water Production, Leeuwarden, The Netherlands, 10-12 September 2012. Although the method was originally conceived for application to subterranean brackish waters in the Canary Islands, Spain (principally Gran Canaria, Fuerteventura and Tenerife), it can be extrapolated to other types of region and water treatable with RO systems. The required input data are the chemical composition of the feed water, pH, temperature, SDI, membrane manufacturer design guidelines, and the plant production. The programmed method determines the design of the RO system (arrangement) and the operating pressure so as the quality of the product water for different operating years and different types of the RO elements. The method whose procedure is described graphically and analytically can be used as an aid in design optimization of RO brackish water desalination plants with acid-free pre-treatment processes and by the use of scale inhibitor using spiral wound membranes. Practical applications are presented. Calculations and simulations for different types of feed water and capacities are showed. A comparison between the values obtained by this method and from membranes manufacturer software is shown so as the comparison between these and the real values from different desalination plants.