Talk:Desalination

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[edit] References and External links

Please, could someone look up all links in "References and External links" on the end of the page. Some are 404 (# The Desal Response Group), total commercial and so on (1 "Desalination" (definition), The American Heritage Science Dictionary, Houghton Mifflin Company, via dictionary.com. Retrieved on 2007-08-19.) . Thanks re03955 14:21, 7 January 2008 (UTC)


What is "pressure barrier osmosis"? Google finds only Wikipedia articles. This term appeared first in water resources (first version).--80.137.207.121 21:18, 13 Aug 2004 (UTC)

I haven't been able to find anything to confirm the existance of such a thing. Failing the arrival of confirming references that I can actually see, I will probably remove the reference to "pressure barrier osmosis" next month. --Coro 21:58, 29 Mar 2005 (UTC)

I never heard of it either. Probably a confusion with reverse osmosis. pstudier 01:19, 2005 Mar 30 (UTC)

[edit] additional citations for verification

Encyclopedia of Desalination and Water Resources (DESWARE) http://www.desware.net/des3.aspx —Preceding unsigned comment added by Manic mechanic (talk • contribs) 03:36, 31 December 2007 (UTC)

[edit] Energy

How much energy is needed to desalinate a cubic meter of sea-water? Someone please add this to the article. —The preceding unsigned comment was added by 83.249.20.138 (talk) 19:52, 8 December 2006 (UTC).

A cubic meter? Who measures water that way? Should the answer be provided in millicalories just for fun? Jpp42 13:41, 1 July 2007 (UTC)
If SI is used, this would be good for everybody. I think cubic meter is the best way.re03955 14:21, 7 January 2008 (UTC)

[edit] Gas Hydrates.

The interest in ethane (gas) hydrates is more to do with mining them from the sea floor for their gas and water components to be separated. While being researched for desalination it is certainly not a major process. Moreover it does not yet produce water fit for drinking. I have relegate the process to the list of possible methods... perhaps it can be expanded on its own article. CustardJack 12:03, 10 May 2005 (UTC)

[edit]

I am not sure what Membrane Distillation means. I suspect that it is an old-fashioned term for Membrane Processes and therefore should be removed, since they exist as separate entries under Reverse Osmosis and Nanofiltration (which I have added). However, it may mean what are generally termed "Hybrid Plants", which combine distillation, ie evaporation, with membrane processes and an electricity generating station. This alternative provides flexibility because of its two sources of energy: electricity for the membrane process and low-pressure steam from the power station for the thermal evaporation process (MSF or ME).

WuLouis

Hello WuLouis,

Membrane distillation is a process using material like Gore-Tex for desalination. There have been small applications been set up and research is going on in Germany. Plus for this process is low temperature and pressure. Scaling and fouling is very low! GOR better PR has to be improved during ongoing research at the moment. See also http://de.wikipedia.org/wiki/Membrandestillation

Claus Mertes

Totally forgetting my lack of German, I tried to take a look at the referenced article. Needless to say, I didn't get very far. Any chance of somebody translating to an English version?--Coro 00:09, 4 March 2006 (UTC)
You could try [1]. This is Google's translation of the web page. It seems to me that this would require the same amount of heat as any conventional distillation, but at a lower temperature. Not sure what it's advantage over vacuum distillation. Hope this helps. pstudier 01:55, 4 March 2006 (UTC)

[edit] Misplaced item?

The sentence "While SDSU Center for Advanced Water Technologies [2] and Professor Ronald A. Newcomb has worked with a local company (Aqua Genesis Ltd.) to assist in the development of geothermally powered desalination. [3]" towards the top of the page seems a) to be advertising and b) out of context where it has been placed. Geothermally powered desalination is not a major desalination technology at present. Wulouis

In looking at it, I'm having to agree. That section is supposed to be for currently established methods. I will be moving that stuff down to the experimental section.--Coro 01:10, 26 January 2006 (UTC)

[edit] Spray method

Does anyone recall a method involving spraying the saltwater (creating a fine mist), making distillation require vastly less energy? Apparently boiling the mist saltwater was much easier than boiling it as a liquid.

[edit] First time thermal desalination was published

I did try to find out when thermal desalination (MSF) first was published and fond a Process scheme of a multi stage flash (MSF) evaporator published 23. – 26. May 1934 in Germany during a seminar of “Schiffstechnische Gesellschaft” by Mr. R. Blaum called “Process scheme of a 3-stage flash evaporator plant with brain recirculation” I do have a scan of the process if wanted because I do not know how to get it in here.

Claus Mertes

Postwar, R.S. (Bob) Silver, a Scottish professor of engineering (and poet and playwright), did a thermodynamic analysis that showed multi-stage flash and reverse osmosis were clearly the best processes. Reverse osmosis was at the time technologically infeasible, and I believe that Silver's MSF design was the first continuous-flow process to be commercially implemented, in Kuwait. He was given a UNESCO gold medal for this invention. Bob told me that patents were drafted but did not succeed in catching very much of the huge money that American companies subsequently made. I am not sure how Blaum fitted in; Bob is no longer with us, but his published papers on the subject might say. - AG, Stockport.


Thanks for this information. Talking about a continuous-flow process please have a look at http://de.wikipedia.org/wiki/Meerwasserentsalzung. This is the continuous-flow process published in 1934 by Blaum. - Claus Mertes

[edit] Economics

I added a bunch of [citation needed] disclaimers to the economics section, as it is simple stated facts without references. If anyone has any real information as to the economics and costs of construction/maintenance/etc, I think it would be extremely useful.Dirtyharry2 00:27, 26 September 2006 (UTC)

I am currently the project engineer for supply of GRP pipe to the Gold Coast Desalination project at Tugun in Queensland Australia. You have asked about construction costs and I have figures for the project of: Pretreatment and RO plant: AUD 600M Tunnel for supply and return of salt water: AUD 300M Network piping for fresh water: AUD 300M These are construction cost estimates only that have been given to contractors. 219.89.123.33 23:49, 10 September 2007 (UTC)D Ashby

[edit] Carbon emissions from desalination

I suggest a paragraph or two about carbon dioxide emissions (greenhouse gas) from desalination would be appropriate in this discussion. If the energy intensity of desalination is quantified, it will then be possible to estimate greenhouse emissions for a given electricity source (e.g. coal etc). I do not know the amount of energy required for desalination, but I can quantify the emissions relative to the energy requirement. —The preceding unsigned comment was added by Haimona (talk • contribs) 01:32, 21 March 2007 (UTC).

[edit] There are a lot of grammatical errors in this article

There are a lot of errors with the usage of "and," in regards to run-on sentences. —The preceding unsigned comment was added by Jasdub32 (talk • contribs) 10:52, 26 April 2007 (UTC).

[edit] Expansion requests

 Please help improve this article or section by expanding it.
Further information might be found on the talk page or at requests for expansion. (July 2007)

This article could benefit from:

  • More examples of prices of desalination and alternatives (such as tapping ground, river, or lake water) in various locations around the world. That way readers can make up their own minds about how expensive or infeasible it is.
  • A list quantitatively detailing the suppy capacity on a country-by-country or plant-by-plant basis for the largest facilities in the world.

-- Beland 16:33, 27 June 2007 (UTC)

The World Bank report on desalination in the Middle East and Central Asia has significant useful information on desalination in general, covering the economics, environmental aspects, energy use, and institutional aspects. It could be a useful reference for any expansion of the article: http://siteresources.worldbank.org/INTWSS/Resources/Desal_mainreport-Final2.pdf--Mschiffler (talk) 02:46, 23 April 2008 (UTC)

[edit] Retitle article "water desalination?"

I expanded the opening paragraph to note that desalination means salt removal generally, as with soil desalination. Perhaps this article should be renamed "water desalination" (which currently redirects to desalination), and desalination made into a stub article explaining the general definition, with wiki links to water desalination and soil desalination. -Agyle 23:17, 18 August 2007 (UTC)

[edit] Forward osmosis

"food grade concentrate". What substance is used? It should be made clear that this will not give rise to pure water, but some kind of soup or syrup. 84.43.92.19 17:11, 12 September 2007 (UTC)Michael

That sentence was unreferenced, and I tagged it and other statements in the section as needing citations. According to "Forward Osmosis: A New Approach to Water Purification and Desalination", forward osmosis is used in concentrating food products like fruit juice, but not in desalination. A casual google search of "forward osmosis" (FO) and "desalination" suggests that as of 2006, FO was not used in commercial desalination, and experimental use seems to use ammonia and carbon dioxide rather than food grade concentrate on the non-salt side. -Agyle 07:59, 16 September 2007 (UTC)

[edit] Largest desalination plant is in Israel?

I believe the world's largest desalination plant is in Ashkelon, Israel, it's now providing and selling 165 000 m3 of water per day and will eventually produce 330,000 m3 per day of water daily. Punjabishere (talk) 22:22, 10 February 2008 (UTC)

[edit] Actual power rating

I found in the article only 4 kWh per m³ sea water. This is not state of the art. New systems with pressure recovery are at 2.5 kWh electric power / m³.

Here a desalination cost calulator

When it comes to the task to reduce carbon dioxide to a level before using fossile energy, desalination for irrigation dry areas could be a key technology.

--Pege.founder (talk) 13:06, 2 March 2008 (UTC)

[edit] Clarification

"Sometimes the process produces table salt as a by-product. It is used on many ships and submarines."

  • I can't be sure whether this is referring to the salt being used or the process used on ships and submarines. Any ideas?

"Saudi Arabia's desalination plants account for about 24% of total world capacity."

  • This sounds like the plants account for 24% of all desalination worldwide, but it could also be referring to using 24% of the world's energy capacity. Any ideas? —Preceding unsigned comment added by Neum (talk • contribs) 22:09, 25 March 2008 (UTC)

[edit] COORD template

How is the {{coord}} template relevant for this article? I believe it should be removed. Timneu22 (talk) 16:21, 13 April 2008 (UTC)