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Removing toxic mercury from contaminated water

Water which has been contaminated with mercury and other toxic heavy metals is a major cause of environmental damage and health problems worldwide. Now, researchers from Chalmers University of Technology, Sweden, present a totally new way to clean contaminated water, through an electrochemical process. The results are published in the scientific journal Nature Communications.

“Our results have really exceeded the expectations we had when we started with the technique,” says the research leader Björn Wickman, from Chalmers’ Department of Physics. “Our new method makes it possible to reduce the mercury content in a liquid by more than 99%. This can bring the water well within the margins for safe human consumption.”

According to the World Health Organisation (WHO), mercury is one the most harmful substances for human health. It can influence the nervous system, the development of the brain, and more. It is particularly harmful for children and can also be transmitted from a mother to a child during pregnancy. Furthermore, mercury spreads very easily through nature, and can enter the food chain. Freshwater fish, for example, often contain high levels of mercury. Read more

Can we detect water on exoplanets?

When it comes to astronomy, the good old days aren’t so old. We’ve been studying the heavens for centuries, but our technology is still getting better. While we only discovered an exoplanet (that is, a planet not supported by our solar system) for the first time in 1992, scientists were pretty darn quick to figure out ways to determine the composition of some of Earth’s far-distant cousins.

Glowing a dark magenta, the exoplanet GJ 504b — illustrated here with an artist’s depiction — weighs in at about four times Jupiter’s mass.

Back in the day, we could only determine whether a planet had water by watching it pass in front of its host star during orbit, or by collecting imaging data from planets far enough away from their host stars. That worked reasonably well, but (luckily for us) there were too many cool planets to explore that just didn’t fit that specific description.

What we really needed was a way of looking at planets — outside of super-specific time periods and parameters — that would give us the same concept of what a planet’s atmosphere consisted of, and whether water was a part of it. But how do we get a good look at the light of a planet or star when we can’t track its transit? We look at the non-visible light it emits in the infrared spectrum. That information can then be compared to modeling data to gather all kinds of information about the planet.

Let’s take the planet Tau Boötis b as an example. Found in 1996, Tau Boötis b was the first planet found not by watching its transit (it doesn’t pass in front of its star), but by noticing it exerted a bit of a pull on its star. Using this new spectroscopic technique, scientists were able to confirm its orbit. Read more

Water Wars: Egyptians Condemn Ethiopia’s Nile Dam Project

Projects on the scale of the $4.7 billion, 1.1-mile-long (1.7-kilometer-long) Grand Ethiopian Renaissance Dam often encounter impassioned resistance, but few inspire the kind of dread and fury with which most Egyptians regard plans to dam the Blue Nile River.

Egypt insists Ethiopia’s hydroelectric scheme amounts to a violation of its historic rights, a breach of the 1959 colonial-era agreement that allocated almost three-fourths of the Nile waters to Egypt, and an existential threat to a country largely devoid of alternative freshwater sources.

But what Egyptians regard as a nefarious plot by its historic adversary to control its water supply, Ethiopians see as an intense source of national pride and a symbol of their country’s renewal after the debilitating famines of the 1980s and ’90s. Read more

There’s water inside the moon – More than we thought

THERE’S EVEN MORE water on the moon than we previously thought, according to new analysis of tiny glass beads left over from ancient volcanic eruptions.

The naturally occurring beads were collected in the 1970s as part of the Apollo 15 and 17 missions, which landed near zones of volcanic activity. The beads formed when magma bursting onto the surface crystallized in such a way that water became trapped inside.

Scientists used to think the moon was completely devoid of water, but recent studies have proven that false.

However, scientists couldn’t be sure if the Apollo samples are unique or if other volcanic flows on the moon are filled with water-bearing glass. (Find out how flying oceans of magma help demystify the moon’s creation.)

In a new study published today in Nature Geoscience, scientists reexamined the Apollo samples and used more recent satellite data to look for signs of water-bearing beads elsewhere on the moon. They found that the volcanic deposits are indeed widespread, which suggests that the material inside the moon is wetter than previously thought. Read more

The U.N. and the Sea Grab of Today

It was the Maltese delegate to the United Nations who spoke up first, in November 1967, to urge the members of the U.N. to use their collective clout to come to an agreement on fair and responsible use of the world’s oceans. It took 15 years, but an agreement was eventually struck from a nine-year conference that produced the U.N. Convention on the Law of the Sea.

Because of their importance in navigation, straits like the Strait of Gibraltar (shown off the coast of Tarifa, Spain) remain international waters.

The treaty was completed in 1982 and came into force in 1994. Essentially, it codified already established customs, like the Law of the Sea. International waters remained international, “the common heritage of all mankind” [source: UN]. Limitations were set on how much coastal water and seafloor a nation could claim as its own. The territorial sea, that aquatic boundary along a nation’s coast that extends its terrestrial boundaries, was set at 12 nautical miles (13.8 miles and 22.2 km).

The convention also set clear definitions for types of waters. Straits, for example, cut through two land masses (usually owned by two sovereign nations) and connect two larger bodies of water. They’re usually narrower than the 12-mile territorial sea rule. But due to their infinite value in shipping and defense, providing passageways through land masses, straits have traditionally been viewed as international water, despite their close proximity to sovereign nations’ soil. The U.N. maintained the straits’ position as international waters. Read more