Water desalination, that's not new right?

Question

So there was this tv commercial on how water from the ocean can be desalinated. I thought that was old technology? The commercial made it seem all new and stuff

Answer 1

It is old. It is also expensive, because it takes a lot of energy to remove the salt. You cannot use a regular filter. You either have to distill it, which means boiling it away and then catching and cooling the steam, or you have to pump it through a reverse osmosis filter. Because of the cost, it is rarely done.

Answer 2

While I am sure that water desalination has been around since man first learned to boil water, there are some new twists and new technology being developed that may make it both energy-efficient and reduce the undesirable by-products. I have not seen the commercial, but there are some new advances that may change the economics of desalination.

Some communities in California tried desalination to solve water shortages over a decade ago and still have the capability whenever needed. The Santa Barbara plant uses reverse osmosis membranes to produce potable water from ocean water. The cost as of January 2007 was $1100 per acre foot of water. That's about 326,000 gallons. The plant is powered by electricity, which in the Santa Barbara area is produced by about 51% natural gas, with some inputs from geothermal, wind, and coal-fired power plants. The water is forced through membranes at about 800 psi and the final product, so I have heard (it might have improved lately), is not the best-tasting water. Environmental groups have objected to the waste output of the plant which is returned to the ocean. The plant is not used except when needed, as the water costs are significantly higher than other sources.
See:http://www.countyofsb.org/pwd/water/desalination.htm

The methods currently in use in the Middle East are tried and true - flash distillation. Since petroleum is abundant there and water is not, they can afford to use staged flash distillation to produce high quality potable water.

There are newer high-tech methods that are just being developed:
"Mineral Water Development International, a company based in Stellenbosch, South Africa, is testing a system that uses flow distributors in concert with electromagnetic fields to greatly increase the efficiency of reverse osmosis. "The [system] inhibits the formation of carbonate scales so you don't need acid. [And] it appears to deter biologic fouling on the membrane so you don't need fouling inhibitors," Furukawa says. "Once you eliminate the need for chemicals in the system, then the concentrate of brine is more easily disposed."

These types of improvements could make desalinization practical and economical for many more coastal communities and could also be applied to recycling of waste water, although public opinion and politics tend to stand in opposition to reclamation of water from waste water treatment facilities.

See:
http://www.ehponline.org/docs/2000/108-2/innovations.html

Answer 3

The current water desalination technology is extremely energy intensive so it's essentially a matter of energy. However there are concepts of mimicking biological methods by creating artificial protein membrane with molecular water channels called aquaporins which only allow molecular water to pass. This is how nature filters water. It's also possible to design small ecosystems that use plants to purify water naturally but the liability costs pretty much obviates any profit potential. So you could just invest in energy, i.e.: oil companies thereby investing in the existing water desalination industry, invest in the tech start ups developing aquaporins hoping that they don't just get squashed or bought out and shelved by the energy companies or invest in the various tree hugger organizations trying to bring our society back to a more organic local scale. The profit potential is also in that order with a big drop off in profit potential after the first choice. Our global problems aren't technological, they're socio-economic problems.

Answer 4

Contrary to what a Top Contributor said it is not expensive. They (the City and the Army) are building the largest inland desalinization plant where I live, and with the latest technology it isn't going to be that expensive. Perhaps what you saw was a commercial based on new technology.

Answer 5

The concept is ancient. However, there have been advances
in the methods used for desalinization such as Reverse Osmosis, and using vacuum chambers. Try a search on using google, ask.com, or any other search engine. Then visit the sites of companies that build these systems for better explanations of the technology.

Answer 6

Old technology.

EVAPS have been used on U.S. Navy ships and submarines for decades to make potable water out of salt water.

Answer 7

Old hat.

Any form of media will try to lead you to believe what they want you to believe.

Answer 8

Intresting,im sure its not that new.