Each year American Rivers names 10 of the most threatened waterways in the United States. This year the river flowing through one of America's most iconic landmarks tops the list. A current and proposed dam for the Pearl River (pictured), which runs through Louisiana and Mississippi, puts healthy wetlands and wildlife habitat at risk, the group argues.Top 10 Western River Floats
The Harpeth River in Tennessee faces sewage pollution and excessive water withdrawals, according to the group.Swollen Rivers From Space
A copper-nickel sulfide mine is proposed near Minnesota's St. Louis River, which American Rivers said "threatens drinking water, wildlife, and the treaty-protected hunting, fishing, and gathering rights of the Ojibwe people."1st Antarctic Atmospheric River Found
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The Wild and Scenic Illinois Rogue, in Oregon, and the Smith in parts of Oregon and California, are threatened by strip mining, said the group.What Happens If The Mississippi Runs Dry?
An open-pit coal strip mine is at odds with clean water, the group suggests, and healthy salmon runs in Alaska's Chuitna River.Rare Sight: Colorado River Reaches Gulf: Photos
South Carolina's Edisto River is a popular recreation spot, but is in high demand for irrigation and agriculture.Ancient Canyon Found Under A River In Tibet
The Smith River in Montana is at risk due to a proposed copper mine, American Rivers said, which could affect water quality and animal habitats.Oil Spills Into Yellowstone River After Pipeline Leak
The Holston River in Tennessee provides freshwater to residents but the proximity of a Army ammunition plant creates a dangerous situation, American Rivers said.Dyson Barge To Suck Up River Pollution
Columbia River dams provide clean power and irrigation, but they create barriers to salmon and steelhead runs.Rivers And Mountains Directly Shape Languages
The Colorado River in the Grand Canyon in Arizona faces a host of threats including radioactive pollution from uranium mining, proposed construction projects and increased groundwater pumping that could deplete freshwater supplies, according to the group.Life Surviving In Salty Spanish River Mimics Martians
Particle pollution floating through the air is responsible for millions of deaths annually — what if we could find a way to capture and repurpose those particles into something productive?
Anirudh Sharma is doing just that. The MIT graduate has devised Kaala-printer, a machine capable of turning carbon-rich soot into black printer ink with only two additional, low-cost ingredients: rubbing alcohol and oil.
After soot has been collected in a pump, Kaala-printer attaches to a hacked-up commercial ink cartridge to print at a resolution of 96dpi:
In an interview with Tech Insider, Sharma estimates that a diesel vehicle engine would only take an hour to produce enough soot to fill an ink cartridge.
“With a little bit of research,” he said, “it can become as good as the printing ink HP sells to you.”
Sharma writes on his website that his creation was inspired by life in his home country, India.