Desalination Plant Design

http://en.wikipedia.org/wiki/Desalination

To produce a million gallon per day....the biggest operating cost in a Flash Type Desal is steam. A plant litterally needs upwards of 250,000 lbs/hr of steam. That is achieved with an industrial boiler.

With RO, (I can't say I've seen a million gal/day RO plant) but your big expense is going to be in the acid backwash. This operatation is conducted for every 100,000 to 200,000 FT3 of flow. Acid purchase and disposal costs would be large.

Generally - the industry standard is to tie a desalinization plant into a power gen plant (cogen - for steam and electrical production)

I commissioned one of these facilities for Enron in 1999 in Penuelas Puerto Rico. We used an IDE (Isreali Desal Engineering) 4 stage flash type desal plant (generating 1 million gallons per day of fresh water) and took steam from a combined cycle plant that used 2X Siemens Westinghouse 501F gas turbines and 2x ABB HRSG's.

with the plant you commissioned for enron in 1999 in penuelas puerto rico, what kind of set up was used (i.e. flow chart design of equipment). this would be very helpful to me if possible.

http://blog.scifi.com/tech/archives/2007/05/04/solar_power_pla.html

here is a possible heat source

Use solar to heat the water, then a steam driven electrical turbine to generate power for utilities. The steam will then condense into pure water to be sold! I can envision the whole plant set-up just writing about it.