Desalination, long term solution to Drought

From the above map we learn Saudi Arabia has the most desalination plants in the world:

“eight plants using the reverse osmosis technology and 12 using the multi-stage distillation process. The country has the largest floating desalination plant in the world with a capacity of producing up to 882,867 cubic feet.”

United Arab Emirates, Saudi Arabia, and Israel operate most of the world’s plants, design and build them for other countries.

The above provides a history of desalination, which they tell us has been understood by humans for thousands of years.

….”Greek sailors used to boil water to evaporate fresh water away from the salt, and Romans used clay filters to trap salt.”

The World Bank reports that at least 80 countries have water shortages and 2 billion people lack access to clean water. More disturbingly, the World Health Organization has reported that 1 billion people lack enough water to simply meet their basic needs, unfortunately in many countries water is scarce or contaminated.

Australia’s experience with desalination includes wood-fired stills at the Coolgardie goldfields 100 years ago, solar ponds at Coober Pedy, and electrodialysis for the first plant at Yulara.

There are about 270 desalination plants in Australia, most of them small-scale plants to desalinate seawater or brackish water for a range of uses. This includes drinking water supplies for communities or tourist destinations (e.g. Kangaroo and Rottnest islands), industrial processes, irrigation of sports grounds, and agricultural uses.

Desalination plants have been constructed in major Australian coastal cities to produce large amounts of drinking water for urban populations.

The importance of the history and application of reverse osmosis is explained in the above article. Here are some timeline facts:

…..”Osmosis has taken place for millions of years and happens in our bodies every day.

The process of osmosis through semipermeable membranes was first observed in a laboratory setting in 1748  by Jean-Antoine Nollet, using a pig’s bladder as a membrane. He proved that a solvent could pass selectively through a semi-permeable membrane through the process of natural osmotic pressure and the solvent will continually enter through the cell membrane until dynamic equilibrium is reached on both sides of the bladder.

Over the next 200 years, osmosis was only a phenomenon observed in the laboratory. In 1949, the University of California at Los Angeles was the first to look to osmosis and semipermeable membranes for a solution of removing salt from seawater. Researchers from both the University of California and the University of Florida successfully produced fresh water from seawater in the mid-1950s, however, the product was not commercially viable due to high flux. John Cadotte, of FilmTec Corporation, later discovered that membranes with particularly high flux and low salt passage could be made by interfacial polymerization of m-phenylenediamine and trimesoyl chloride. By 2001, over 15,00 desalination plants were up and running, or planned for, around the world.

The above link explains the desalination plant design which precede the American designed reverse osmosis system.

Multi-stage flash has been superseded by reverse osmosis. Older MSF plants are not environmentally friendly and they are costly, but when introduced were providing vital drinking and irrigation water to desert lands.

Multi-stage flash (MSF) is a thermal desalination process.  It distills water by boiling it under vacuum (also known as flashing), then condensing the pure water vapour.  It uses multiple shell and tube heat exchangers called stages.

MSF was the market leader in terms of sea water desalination for many years.  Around 2009 reverse osmosis overtook MSF as the most popular in terms of installed sea water desalination capacity.

Israel has recently built a highly sophisticated reverse osmosis plant which provides drinking and fresh irrigation water to land hit by 6 years of drought in southern Israel. Gaza lies in the same region but has no such facility although it lies on the coast.

Now Israel has achieved such a respected name for what it has achieved it is building a desalination plant, based in San Diego, California.

“Fast emerging technologies are now making desalination a viable proposition not only for the arid areas of the world but for places not usually associated with water shortages. IDE Technologies, a leading water sector Israeli company which is internationally recognized as a pioneer and leader in the delivery of sophisticated water solutions, is leading the charge.”

Of the new California contract they proudly state:

“Providing a new source of water in a state that has long suffered severe droughts, the Claude “Bud” Lewis Carlsbad Desalination Plant will be quenching the thirst of roughly 10 percent of San Diego County, according to IDE. Employing advanced pretreatment and seawater reverse osmosis technologies, the plant is able to generate potable water of the highest quality while significantly reducing energy consumption.”

Magnesium is lost from drinking water when the salt is removed, therefore magnesium, vital for human health, must be added to the drinking water.

There are many coastal countries in the world whose peoples would not be dying from years of famine caused by long term drought if these same plants were to be built under a rescue plan. Then they could provide for themselves and not need costly aid from foreign intervention. No person should be without fresh, clean water.

About borderslynn

Retired, living in the Scottish Borders after living most of my life in cities in England. I can now indulge my interest in all aspects of living close to nature in a wild landscape. I live on what was once the Iapetus Ocean which took millions of years to travel from the Southern Hemisphere to here in the Northern Hemisphere. That set me thinking and questioning and seeking answers. In 1998 I co-wrote Millennium Countdown (US)/ A Business Guide to the Year 2000 (UK) see
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