PRETREATMENT PROCEDURES TO CONTROL BIOGROWTH AND SCALE FORMATION IN MEMBRANE SYSTEMS

The Middle East region is regarded as the cradle of desalting, having many of the world's largest membrane systems in addition to extensive thermal distillation plants. Many important design and operation techn iques have been developed and perfected in the region because of the n eed to solve problems locally. Efficient pretreatment design and opera tion is essential for the optimisation of RO plant performance irrespe ctive of whether the feed source is natural or waste water. Poorly des igned pretreatment and inadequate plant maintenance has often resulted in membrane failure and tarnished the reputation of the reverse osmos is process. This paper examines the importance of monitoring pretreatm ent plant used to control microbiological and general fouling and inhi biting the formation of inorganic scales. The paper gives examples of systems which have experienced problems and the technical recommendati ons made to improve pretreatment so as to improve membrane performance and operating and costs.