Study highlights growing toxic brine problem

BERLIN – The world’s thirst for fresh water is causing a salty problem.

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, according to a UN-backed report released Monday.

The study by researchers from Canada, the Netherlands and South Korea warned that much of the brine is being dumped untreated into the sea, and some is laden with toxic chemicals, causing harm to sea life.

The authors called for better brine management, particularly in countries that rely heavily on desalination for their water needs, such as Saudi Arabia, the United Arab Emirates, Kuwait and Qatar.

“We know that water scarcity is increasing in many regions across the world due to increased water demands, which are associated with population increase and economic growth,” said one of the authors, Manzoor Qadir, assistant director of the United Nations University’s Canada-based Institute for Water, Environment and Health (UNU-INWEH).

At the same, climate change is making the availability of freshwater less predictable, such as by changing the amount of runoff snow in some regions, he said.

The authors examined 16,000 desalination plants worldwide and found they produce 142 million cubic meters (5,014 million cubic feet) of brine each day, or 51.8 billion cubic meters a year. That’s about half more than previous studies had estimated, Qadir 9said.

The researchers called for better brine management, noting that studies have shown it can be used in aquacultures to boost yields of salt-tolerant species of fish, and the metals and salts contained in it – such as magnesium and lithium – could be mined.

Brine, water comprising about five percent salt, often includes toxins such as chlorine and copper used in desalination, it said. By contrast, global seawater is about 3.5 percent salt.

Waste chemicals “accumulate in the environment and can have toxic effects in fish,” said Edward Jones, the lead author at UNU-INWEH who also works at Wageningen University in the Netherlands.

Brine can cut levels of oxygen in seawater near desalination plants with “profound impacts” on shellfish, crabs and other creatures on the seabed, leading to “ecological effects observable throughout the food chain,” he said.

Vladimir Smakhtin, director of UNU-INWEH, said the study was part of research into how best to secure fresh water for a rising population without harming the environment.

Lakes, rivers

“There are all sorts of under-appreciated sources of water,” he said, ranging from fog harvesting to aquifers below the seabed. The study also involved the Gwangju Institute of Science and Technology in South Korea.

Brine from desalination plants that tap brackish lakes, aquifers or rivers far inland is harder to treat than brine from coastal plants that can be piped into the seas.

Gurpal Toor, a water quality expert at the University of Maryland who was not involved in the study, said brine “could be a serious issue in a small body of water” like an inland lake.

Brine can be used inland for irrigating salt-tolerant crops, for fish farming or to produce table salt, he said.

Alex Drak, an engineer at IDE Technologies in Israel, a leading water treatment firm, said properly processed brine from coastal plants dissolves quickly in the sea.

“We see a lot of marine life, different types of fish, in the vicinity to the discharge point,” said Drak, who was not involved in the UNU study. – Reuters