SCALE FORMATION AND FOULING PROBLEMS EFFECT ON THE PERFORMANCE OF MSF AND RO DESALINATION PLANTS IN SAUDI-ARABIA

Most people working in water desalination recognize that scale formation and fouling problems are facts of their practical life. Seawater and brackish water always have the tendency for scale formation and fouling problems due to dissolved salts and finely suspended solids. Elaborate models are available to simulate these scale and fouling problems to help the design engineer to predict the effects of such problems on the performance of the desalination plants. From the practical point of view, main types of scales in MSF plants are CaCO3, Mg(OH)2 and CaSO4 while in the RO plants biofouling of the membranes is a major problem. The present paper investigates the various models and mechanisms of scale formation and biofouling processes in water desalination plants and discusses proper pretreatment methods and scale control techniques to minimize the drastic effects on the performance of desalination plants in Saudia Arabia. The interaction between scale formation, biofouling and corrosion problems in both MSF and RO desalination plants are discussed and recommendations are given for both design engineers and operators for overcoming such scale and fouling problems in desalination plants.