Tetsuo Mizuniwa

Field experience of seawater desalination by reverse osmosis system, operating in Saudi Arabia

Abstract The reverse osmosis system has been broadening its application capability for these several years. Especially in recent years, there have been substantial approaches to seawater desalination, proving technical and economical viabilities to generate fresh water from the sea. A seawater reverse osmosis plant has been operating successfully since January 1977 at Ras Al Khafji, Saudi Arabia, producing the product water of 200 to 300 ppm TDS from the seawater with a high salinity of about 45,000 ppm TDS. The pretreatment process consists of coagulation/clarification, dual media filtration and polishing sand filtration along with the appropriate chemical dosages. The seawater desalination employes a two-stage reverse osmosis plant of 40 M3/D in capacity, using ROGA 6085 CTA modules and ROGA 4160HR modules respectively for the first-stage and for the second-stage. The brine concentrate from the second-stage is recycled back to the feedwater inlet of the first-stage. The two-stage RO seawater desalination system is proving greater reliability and better performance: the product water quality is maintained safely within the recommended limitation of the WHO drinking water standard.