A water-wheel proves great at preventing plastics from polluting the oceans
We use a lot of plastic, but unfortunately, we don’t hold on to it. All too often it finds its way out to sea, where it has been accumulating in every major ocean on earth. More than just an ugly comment on how much waste humans create, this plastic breaks down just enough to emit chemicals potentially harmful to ocean ecologies. Cleaning up this mess is a huge, at this point impractical undertaking, but preventing more of it may be within the grasp of even individual cities.
Baltimore, MD, with help from the Waterfront Partnership, has built a wonderfully simple yet effective trash-catcher at the mouth of the Jones Falls river, where it meets with the Baltimore Inner Harbor, and then the ocean. The device is basically a large waterwheel that scoops trash out of the water before it heads out to the ocean. With the help of booms that funnel trash away from the shore, the wheel uses the water’s currents (or solar power, if need be) to lift trash up, filling a removable dumpster at the back. The only human intervention needed is to empty the dumpster, resulting in a very low-cost, and therefore attractive, way to prevent pollution.
It’s also very effective. The, ahem, high water mark has been 19 tons of trash removed in 24 hours, after heavy rain carried enormous amounts of junk down the river in April . Special events like the Preakness Stakes lead to the dumpster needing to be emptied every hour (seriously, what is happening at these horse races?) One year’s 145 tons of prevented pollution far exceeds what other major cleanup efforts normally bring in. But while the wheel is great at catching bottles, cigarette butts, and a surprising number of plastic toys, it does have problems with things like plastic bags that can slip past the booms. So while it’s not the final word in pollution prevention, it’s combination of effectiveness plus low costs have inspired other cities to try the idea.
Source: Baltimore’s Garbage Wheel by Andrew David Thaler, Hakai Magazine