Desalination Produces More Toxic Waste Than Clean Water – Study

 

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, published Monday.

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 30-centimetre (one-foot) 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, told AFP.

“Almost all the brine goes back into the environment, mostly in the ocean.”

All that extra salt raises the temperature of coastal waters, and decreases the level of oxygen, which can create “dead zones”.

“It is difficult for aquatic organisms to breathe in these conditions — they need O2 to survive,” said Qadir.

More than half of the brine comes from only four countries: Saudi Arabia (22 percent), United Arab Emirates (20.2 percent), Kuwait (6 percent) and Qatar (5.8 percent).

North Africa, the Middle East, and water-starved small island states in the Pacific and elsewhere also rely heavily on desalination to provide safe drinking water, which accounts for nearly two-thirds of consumption.

The rest is used in industry, as a coolant in energy production, and in agriculture.

Around one in four people live in regions where water resources are insufficient during part of the year, and half-a-billion experience water scarcity year round, according to the United Nations.

Water Scarcity

Since 2015, the World Economic Forum’s annual Global Risk Report has consistently ranked “water crises” as among the global threats — above natural disasters, mass migration and cyber-attacks.

Water scarcity is caused by many things, starting with a global population closing in on eight billion.

Major rivers no longer reach the sea, aquifers are being sucked dry, and pollution is tainting water above ground and below.

With climate change, the situation will get worse.

For each degree of global warming, about seven percent of the world’s population — half-a-billion people — will have 20 percent less freshwater, according to the Intergovernmental Panel on Climate Change (IPCC).

“Desalination technology has benefited a large number of people,” said Qadir. “But we cannot ignore the production of brine, which is going to become an even greater problem in the future.”

Industrial-scale technology for removing salt from water has been around since the 1960s. By 1990, there were already 3,000 plants in operation around the globe.

On current trends, the sector will see a total of at least 17,500 plants by 2025, Qadir said, noting that one large plant can produce as much fresh water — and brine — as 200 or 300 small ones.

More than 90 percent of desalination plants are in wealthy economies. This reflects the fact that the technology remains expensive, especially in energy costs.

But it also means that rich nations have the capacity to develop ways to dispose of toxic brine that are less harmful to ocean and land environments, he added.

Some pilot projects have even shown that modified brine can boost yields of certain fish species in aquaculture.

Global Warming: World’s Oceans Heating Up At Increased Rate – Study

 

The world’s oceans are heating up at an accelerating pace as global warming threatens a diverse range of marine life and a major food supply for the planet, researchers said.

The findings in the US journal Science, led by the Chinese Academy of Sciences, debunk previous reports that suggested a so-called pause in global warming in recent years.

The latest technology shows no such hiatus ever existed, raising new concerns about the pace of climate change and its effect on the planet’s main buffer – the oceans.

“Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought,” said co-author Zeke Hausfather, a graduate student in the Energy and Resources Group at the University of California, Berkeley.

About 93 per cent of excess heat — trapped around the Earth by greenhouse gases that come from the burning of fossil fuels — accumulates in the world’s oceans.

The latest report relied on four studies, published between 2014 and 2017, that gave more precise estimates of past trends in ocean heat, allowing scientists to update past research and hone predictions for the future.

Floating robots

A key factor in the more accurate numbers is an ocean monitoring fleet called Argo, which includes nearly 4,000 floating robots that “drift throughout the world’s oceans, every few days diving to a depth of 2,000 meters (yards) and measuring the ocean’s temperature, pH, salinity and other bits of information as they rise back up,” said the report.

Argo “has provided consistent and widespread data on ocean heat content since the mid-2000s,” it said.

The new analysis shows warming in the oceans is on pace with measurements of rising air temperature.

And if nothing is done to reduce greenhouse gases, “models predict that the temperature of the top 2,000 meters of the world’s oceans will rise 0.78 degrees Celsius by the end of the century,” it said.

The thermal expansion — water swelling as it warms — would raise sea level 12 inches (30 centimetres), above any sea level rise from melting glaciers and ice sheets.

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that,” Hausfather said.

“The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”

“If the ocean wasn’t absorbing as much heat, the surface of the land would heat up much faster than it is right now,” Malin Pinsky, an associate professor in the department of ecology, evolution and natural resources at Rutgers University, told The New York Times. “In fact, the ocean is saving us from massive warming right now.”

Laure Zanna, an associate professor of climate physics at the University of Oxford and who was not involved in the study, told the Times the new research was “a very nice summary of what we know of the ocean and how far the new estimates have come together.”

“We are warming the planet but the ocean is not warming evenly, so different places warm more than others,” Zanna said, according to the paper. “And so the first consequence will be that sea level will be different in different places depending on the warming.”

U.S. Warship Indianapolis Found 18,000 Feet Deep In Pacific Ocean

Photo: Wikimedia Commons

More than seven decades after a Japanese torpedo sank the U.S.S. Indianapolis, researchers have located its wreckage at the bottom of the Pacific.

The U.S. Warship was hit as it was returning from its mission to deliver components for the atomic bomb that was dropped on Hiroshima.

It when down in just 12 minutes and sent no distress signal.

Although 800 of its nearly 1,200 crew survived the attack, only 316 were rescued five days later.

The rest were either killed by sharks or died from exposure, dehydration or drowning.

It’s an incident famously recounted in the movie JAWS by rugged shark hunter and World War 2 vet Captain Quint.

A research team led by Microsoft Corp co-founder Paul Allen revived the search in 2016 after a Navy historian unearthed new information about its last movements.

“We try to do this both as really exciting examples of under-water archeology and as tributes to the brave men that went down in these ships,” Allen said.

The team spent months scouring a 600-square-mile (1,500-square-kilometer) patch of ocean… before finally locating the wreckage, on Friday.

The U.S. Navy says it plans to honor the 22 survivors from the Indianapolis still alive along with the families of the ship’s crew.