Recycle Sea Water?

Question

Tell me this, the ice bergs are melting and the sea level is rising yet in the UK we have hose pipe bans because there is not enough water. Waste water gets cleand and recycled so we can drink and wash with it, why can we not do the same with the sea? there is so much of it and it would solve so many problems. If they can clean and purify other water why not the sea?

What are your views?

Answer 1

Bacteria, impurities (ie. suspended solid, debris etc), odor can be chemically removed from readily fresh water.  The price to do that is cheaper.

Converting sea water into fresh water takes higher cost. You have to remove brine physically (reverse osmosis or evaporation) besides killing and removing micro organism.

Answer 2

the cost of managing the waste from desalination is not cost effective at this point,

Answer 3

Cost of desalination is high and frankly the water companies are lazy.

Answer 4

seawater cantains ahigher concentration of impurities than does dirtied fresh water (generally). So the cost ofcleanig waste fresh water is usually cheaper than desalination. In some contries there simply isnt enough fresh water to go around so desalination of sea water is used. The main cost is energy. So if you have lots of cheap energy (as they do in Saudi) then you can dsalinate as much water as you like. For ships, it makes sense to desalinate as you go, because it would cost you money to carry all you need with you. And for a navy vessel there is the added benifit of being less dependant on land sources.

For a country to use sea water desalination it has to really have exhausted all other options.  Its an economic decision. not a technical one. By the way there is no chance of using up all the sea water so that fish have no where to swim. All water (well nearly all) returns to the sea. you could not drain it, ever.

But are you prepared to pay the higher price for water that would result if sea water desalination were more common?

The engineering is easy, distilation, using a reboiler so that the condensing steam is used to boil the next lot of water, in several stages, each stage at a lower pressure, to get the most out of the heat. Or solar stills, using 'free' sunlight and only one step, (cost of construction is high unless you have lots of cloudless days) or the alternative method of reverse osmosis, pumping the water through molecular sives at very high pressure, the water passes through the salf and anthing else stays behind. But whatever method is used the cost is generally higher than alternatives.

Answer 5

Alot of places around the sea in europe use sea water for the showers and toilets.

Answer 6

Every ship uses desalination for there drinking and shower water. It is simply salt water boiled and the steam separated then cooled from evaporation into fresh water and treated with the normal chemicals used in every day water consumption. It's acutually cheap to do and produce. You can do it at home. I was a boilerman and a water tester in the Navy for six years. But just try to get the Government to do something cheap for the people and not receive a lot of revinue from it and you got world war three started.

                                       Sincerely yours,

                                        Fred M. Hunter

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