PREDICTION OF RO MEMBRANE PERFORMANCE FOR ARABIAN GULF SEAWATER

Arabian Gulf seawater is characterized by its high average seasonal te mperatures, silt density index (SDI), and total dissolved solids (TDS) , in addition to other parameters such as level of pollution and type and magnitude of marine microorganisms. The overall effect of these on RO membrane performance is very significant and complex as well. Henc e, the primary objective of this paper is to present a mathematical mo del for the prediction of RO membrane performance for Arabian Gulf sea water under the prevailing local conditions. A complete system of equa tions that can be used for the prediction of product water now rate an d separation of ions present in seawater for a given RO membrane was o btained on the basis of the Kimura-Sourirajan analysis. Solution of th is system for the purpose of performance prediction requires prior kno wledge of certain parameters that are specific to the RO membrane unde r consideration and pertinent to the ions present in the seawater. A c omputer program has been developed to evaluate such parameters, solve the obtained system of equations, and process the performance predicti ons utilizing experimental data available from the operation of two RO membrane systems, spiral wound and hollow fiber, at the Doha Desalina tion Research Plant (DRP). Comparisons between predicted and experimen tal data at standard conditions have shown reasonable agreement for pr oduct flow rates and very good agreement for the rejection of total sa lts and ions present in the seawater.