Companies such as GE, Siemens and ITT have expanded their water treatment and flow product lines to include the equipment and chemicals necessary for each step in desalination from primary filtration through secondary filtration and finally to the reverse osmosis process.

The market for these products this year will be $2.1 billion and the average growth rate will be 9 percent worldwide over the next five years. These totals are included in a series of online reports available from the McIlvaine Company.

Cross-flow equipment including the membrane modules represents the largest market segment.

The cross-flow revenues are primarily for reverse osmosis but ultrafiltration is commonly used for pre-filtration. Valves are expensive due to the requirements for corrosion resistance. Pumps are critical in supplying the large pressures required in reverse osmosis.

Chemicals are required for coagulating non-settleable solids in the pre-filtration segment. Clarifiers and granular media filters provide the separation of the large particles.

Other chemical needs are for pH adjustment, disinfection, dechlorination, and inhibition of scale.

Secondary filtration involves cartridges or ultrafiltration and is critical to protecting the reverse osmonsis membrane systems from fouling.

The markets for desalination are dispersed around the globe. The leading countries in order of purchases in 2005 are:

• United States
• Saudi Arabia
• Japan
• Spain
• South Korea
• India
• Iraq
• Germany
• Singapore
• China