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Here in my place there is a shortage of river water during these days because of lack of rain. People are demanding to use sea water where we can so please suggest the ways in which we can use sea water...

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    Presuming you don't want to use sea water just at the beach, do you have the necessary infrastructure to build a pump? Also, for what do you need the water, other than in the kitchen and in the bathroom? Would it be possible to reduce the amount of water that every household uses? Are there periods, where the river carries more water than at other times? – Earthliŋ Apr 17 '13 at 4:35
  • @user1205935 yes people are demanding water .. and also reduce the use of water – Yadav Chetan Apr 17 '13 at 5:07
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    Demanding drinking water? I think it is quite difficult to produce drinking water from sea water. Salt is usually taken in through food and water is expected to be salt-free. You can certainly bathe in hot sea water and then rinse your body with fresh water. But to get rid of the salt content, you have to distil the water, which uses a lot of energy, especially when you are in need of large quantities. – Earthliŋ Apr 17 '13 at 5:13
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    Do you live in a place with a lot of sun? – Earthliŋ Apr 17 '13 at 5:20
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    Have a look at solar stills. – Earthliŋ Apr 17 '13 at 5:23
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To produce fresh water from sea water sustainably (i.e. sustainable in usage, if not in production), I think solar stills are your best bet.

The article "Solar Thermal Technologies for Seawater Desalination: state of the art" by Jenny Lindblom (PDF) states that a single-layer solar still can produce up to 6 litres per day, per square metre. More intricate (double-layer) designs may provide better insulation and consequently yield even more water.

For long-term improvement, I would also consider investigating why the river now carries less water than before. An forest upstream may be able to store a lot of water, induce rain and stabilize the flow of the river.

Irrespective of the abundance or shortening of water, it would also be a good idea to reduce the use of water in the household & reuse grey water where possible.

Seawater itself may have other applications as well. One example would be a seawater greenhouse.

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    You are welcome. I would be glad if you'd consider posting your experience & problems you have along the way again here as a new question. – Earthliŋ Apr 17 '13 at 5:59
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    yeah its nice community where i can share the problems and with good response – Yadav Chetan Apr 17 '13 at 6:03
  • But it's still very young. Anyone who comes across a real-life problem, chooses to post it here and is then willing to test the answers s/he gets here would be a very valuable addition to this site. – Earthliŋ Apr 17 '13 at 6:07
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What do we use water for in every-day life? And can we use untreated seawater instead? Because: untreated seawater is what the PO's is supposed to use instead of fresh water. :)

  • Bathing. Maybe Either in the sea or in the bathtub. Yes, if you want to cool down and don't mind the salt. No, not if you want to get really clean. Or should we update our definition of 'clean'?
  • Cooking: **No / Maybe ** Interesting. Food is salty of savoury and boiling it kills bacteria, but might still be too contaminated. (see comments). How about steaming food?
  • Drinking: No
  • Doing dishes. Yes, maybe. But you might want to rinse them with a bit of fresh water afterward. But it could still help
  • Laundry: Maybe. Help needed answering this. Is salt bad for my clothes? Does salt effect the effectiveness of soap? (The comments suggest it does so in a negative way)
  • Flushing the toilet. Maybe (see comments) The sewege system might not like the salt water.
  • Washing my hands. Yes (?)
  • Showering. Maybe. See --> Bathing
  • Irigation (not pictured). No. Salt is not good for the land.

Reference: this picture (How much water do you use in liters) How much water do you use in litersSource: https://www.vitens.nl/service/hoeveel-water-gebruiken-we-per-dag

Disclaimer: this is not a 100% complete answer. I hope it contributes by providing a list and some quantitative data on the current use of fresh water. I hope it will start a discussion, so we can fill in the maybe's The answers I've written after every application are only intuitive.

  • I have some doubts if boiling sea water is enough to filter out harmful substances and use it for cooking. Also the salt content of sea water is rather high, so you would need to add very little. – THelper Aug 14 '18 at 7:50
  • @THelper Thanks! With 'substances' do you mean: chemical pollution of the sea? – Ideogram Aug 14 '18 at 8:20
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    Yes, basically everything that's in sea water and you don't want to ingest; chemicals, feces, tiny plastic particles, sand. – THelper Aug 14 '18 at 8:53
  • Generally speaking the mineral content of the water does affect the effectiveness of soap negatively and also affects the fibres (and colouring) of textiles. I don't think you can use salt water for laundry. – Earthliŋ Aug 14 '18 at 11:35
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    Also, flushing the toilet with salt water is not necessarily a good idea. Again, the mineral content will affect piping and if the waste water is not dumped in the ocean (which would not be good as it would pollute the ocean), it will either have to be treated to make fresh water (at which point the salt will have to be removed anyway) or it will be dumped on the land, where the salinity will slow down or even prevent the natural breakdown of organic material. – Earthliŋ Aug 14 '18 at 11:40
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I think that for the most part of our daily use sea water can be used directly ( of course after proper filtering ).

Except for drinking why do we need fresh water, cannot saline water serve the same purpose. If there is a proper filtering set up ( just the same that we use for our city water supply ) then we can use sea water ( filtered ) for almost most of our daily use. Use a small desalination unit only for getting water for drinking and cooking. For all other use sea water can serve the same purpose.

It is more our mental thinking that sea water in not pure that prevents its use for general purpose.

Only precaution to be taken is to use PVC or other plastic for piping to prevent corrosion. Why cant even Municipal corporations use sea water ( filtered properly ) for even town supply using plastic pipes for transporting the water.

Some of the information contained in this post requires additional references. Please edit to add citations to reliable sources that support the assertions made here. Unsourced material may be disputed or deleted.

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    Welcome to the site and thanks for your contribution! If you provide some links to material that backs up your statements it, or explains details, it is really helpful to readers. – Highly Irregular Jan 22 '15 at 7:58
  • Yeah you sure can wash vegetables and cook rice with see water. But will it work well in a regular wash-machine? – J. Chomel Aug 17 '18 at 6:51

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