The Dirty Truth about Turning Seawater into Drinking Water:
As countries in the Middle East, Africa, and elsewhere struggle to find enough freshwater to meet demand, they're increasingly turned to the ocean. Desalination plants, located in 177 countries, can help turn seawater into freshwater. Unfortunately, these plants also produce a lot of waste—more waste, in fact, than water for people to drink.
A paper published Monday by United Nations University's Institute for Water, Environment, and Health in the journal Science of the Total Environment found that desalination plants globally produce enough brine—a salty, chemical-laden byproduct—in a year to cover all of Florida in nearly a foot of it. That's a lot of brine.
In fact, the study concluded that for every liter of freshwater a plant produces, 0.4 gallons (1.5 liters) of brine are produced on average. For all the 15,906 plants around the world, that means 37.5 billion gallons (142 billion liters) of this salty-ass junk every day. Brine production in just four Middle Eastern countries—Saudi Arabia, Kuwait, Qatar, and the United Arab Emirates—accounts for more than half of this.
[...] "Brine underflows deplete dissolved oxygen in the receiving waters," said lead author Edward Jones, who worked at the institute and is now at Wageningen University in the Netherlands, in a press release. "High salinity and reduced dissolved oxygen levels can have profound impacts on benthic organisms, which can translate into ecological effects observable throughout the food chain."
Whatever happened to the idea of towing icebergs to where water was needed?
(Score: 2) by ElizabethGreene on Thursday January 17 2019, @04:01PM
> I think the issue is that those materials become a problem when they are concentrated.
This is accurate. The core problem is that the difference in saline concentration is enough to encourage the two solutions to stratify. That means the concentrated seawater remains concentrated instead of mixing with unconcentrated seawater. This stratification is how you get brine lakes and deoxygenated zones that damage benthic organisms. If you dilute the wastewater you can greatly reduce this effect.