An integrative approach for optimal membrane selection concerning desalting of brackish water is proposed. This approach is based on management modeling for the following subsystems: Intake, pretreatment, Reverse-Osmosis (RO) unit, post-treatment and brine disposal. The management modeling takes into account membrane performance considerations that include treatment levels and technical capabilities. Attention is also given to membrane replacement and permeates salinity.
The model is based on defining an objective (cost) function to be optimized. The optimum of the objective function is evaluated, subject to a series of technological and economical constraints. The results provide guidelines for optimal membrane selection, pretreatment technology and information regarding the system layout, optimal investment and water cost. According to the results, a design based on gravity filters and high flux membranes is preferred with respect to minimum permeate cost. Analyzing the results, indicates the sensitivity of the solution to interest rate and electric power cost.