Before raw water is desalinated, the undesirable materials will be removed or reduced to acceptable levels. Such materials to be removed include solids, immiscible liquids, and sparingly soluble salts. Accumulations of these materials on desalination process surfaces greatly reduce efficiencies. Without adequate pretreatment, desalination facilities are destined for reduced lifetimes, shortened periods of operation, and high maintenance. Course Outline 1. SITE SELECTION 2. WATER SOURCE SELECTION 3. GENERAL PROCESS SELECTION 4. PRETREATMENT CONSIDERATIONS This is an introduction to the materials and methods recommended for pretreatment of source water for water desalination processes.

Learning Objectives

• Learn about physical and chemical treatment processes used to remove solid materials;
• Learn how most common organic materials, such as tannins and humic acids, can be removed from water by chemical treatment;
• Learn the importance of pH adjustment for optimal performance of desalination systems;
• Learn how to inhibit formation of scale to maintain the efficiency of product water recovery during plant operation;
• Learn the two ways degasification and deaeration of feed water can be accomplished;
• Learn about single-, dual- and mixed-media filtration techniques.
• Learn how to employ filtration with granular media in pretreatment systems.