Skip to player
Skip to main content
Skip to footer
Search
Connect
Watch fullscreen
Like
Comments
Bookmark
Share
Add to Playlist
Report
How does a desalination plant work?
DW (English)
Follow
12/18/2024
Two different processes are used to obtain freshwater from saltwater – distillation and reverse osmosis. It takes around 100 liters of seawater to produce 45 liters of drinking water. Our viewer question this time comes from Richard Z. in Colombia.
Category
🗞
News
Transcript
Display full video transcript
00:00
How does a desalination plant work?
00:05
There are various ways of turning seawater into fresh water.
00:09
Two methods are commonly used on an industrial scale.
00:12
The first is distillation.
00:15
Under vacuum pressure, seawater is heated to 115 degrees Celsius.
00:20
As the water vaporizes, it leaves the salt behind.
00:24
The vapor flows through a cooled pipe, turning to fresh water.
00:28
But of the more than 20,000 desalination plants worldwide,
00:32
only about 20% use distillation.
00:35
The second method is reverse osmosis.
00:38
In this method, water is forced under pressure through a membrane.
00:42
The semipermeable membrane lets water molecules pass through
00:46
while blocking substances like salt and minerals.
00:49
The water on the one side is salt-free, while the other is very salty.
00:54
Even though the cost of desalination has dropped, it's still expensive.
00:58
Obtaining drinking water from 1,000 litres of river water costs just 5 Eurocents,
01:05
while just 1 litre of seawater costs 50 Eurocents.
01:10
In addition, both methods require a great deal of energy,
01:14
much of which still comes from fossil fuels.
01:18
But some smaller desalination plants can now meet their energy needs
01:22
with renewable sources.
01:26
Obtaining 45 litres of pure water through desalination
01:30
requires 100 litres of seawater.
01:33
What's left is called brine.
01:35
It's extremely salty, low in oxygen and often contaminated with chemicals.
01:40
Before it's pumped back into the ocean,
01:43
sometimes some of the salt, sodium chloride, is filtered out.
01:47
But the brine also contains magnesium and potassium,
01:51
which have commercial uses.
01:54
However, extracting these minerals is costly and energy-intensive.
02:00
Researchers are exploring nanofilters and other methods
02:04
to see how valuable minerals and elements can be recovered from brine more efficiently.
Recommended
1:09
|
Up next
Worth its salt: Can desalination help address Europe's freshwater needs?
euronews (in English)
10/1/2024
2:04
The ways we waste water
DW (English)
3/9/2021
1:15
Turning saltwater into drinking water: A low carbon tech solution to the global water crisis?
euronews (in English)
10/6/2023
5:20
What If All the Sea Water Becomes Fresh Water?
WHAT IF
2/21/2024
1:00
What is desalination and how could it help Cape Town during its water crisis?
AccuWeather
2/19/2018
3:05
How do our sewers get blocked? And what is done to clear them?
The News, Portsmouth
11/26/2024
2:43
Under-fire Thai government to push ahead with cabinet reshuffle
The Star
yesterday
1:48
Court sets Aug 1 for graft case mention involving Hamzah's ex-aide
The Star
yesterday
1:44
Na'imah's lawyers dismayed by NFA decision on her police report
The Star
yesterday
3:05
Short track-Do you know what happens During sexual arousal inside the body_ what is the clitoris_
A To Z Videos
10/5/2022
6:30
Do you know how orgasm is in females_ female body and biology
A To Z Videos
10/5/2022
3:33
DONT FAP (Omegle & Chatroulette Funny Moments #82)
Aysesen2016
10/14/2015
5:53
Kolkata women escape sex work to make money in recycling
DW (English)
yesterday
4:09
Pumpernickel — a quirky Westphalian bread creation
DW (English)
yesterday
3:31
GirlZOffMute —Nigeria:The most beautiful girl in the world. Where is she now?
DW (English)
yesterday
1:43
NATO's defense spending boost draws protest
DW (English)
yesterday
3:52
Italian vet fights for Europe's hedgehogs
DW (English)
yesterday
6:00
Situation in Iran, Middle East 'precarious' after US strikes
DW (English)
yesterday
4:30
L’Après M — McDonald's restaurant becomes social hub
DW (English)
2 days ago
5:42
Online dating: How do Europeans really find love?
DW (English)
3 days ago
1:19
Barbara Massing set to head Deutsche Welle
DW (English)
3 days ago
3:37
Is South Africa the right voice for Africa on energy?
DW (English)
3 days ago
12:35
Populist upset: Poland swings back to the right
DW (English)
3 days ago
12:35
One of the best: Indonesian paraglider pilot Jafro Megawanto
DW (English)
4 days ago
3:29
Tourism boom: How Albania is finding its niche
DW (English)
4 days ago
