Desalination plants worldwide produce more toxic waste than fresh water, UN-backed study shows
- Desalination plants around the world are producing enough brine waste to swamp an area the size of Florida with a foot of salty water every year
- Researchers warn that much of the brine is being dumped untreated into the sea, and some is laden with toxic chemicals, causing harm to sea life
More than 16,000 desalination plants scattered across the globe produce far more toxic sludge than fresh water, according to a first global assessment of the sector’s industrial waste.
For every litre of fresh water extracted from the sea or brackish waterways, a litre-and-a-half of salty slurry, called brine, is dumped directly back into the ocean or the ground.
The super-salty substance is made even more toxic by the chemicals used in the desalination process, researchers reported in the journal Science of the Total Environment.
Copper and chlorine, for example, are both commonly used.
The amount of brine produced worldwide every year – more than 50 billion cubic metres – is enough to cover the state of Florida, or England and Wales combined, in a 30cm layer of salty slime, they calculated.
“The world produces less desalinated water than brine,” co-author Manzoor Qadir, a scientist at the Institute for Water, Environment and Health at United Nations University in Ontario, Canada, said.