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VOA常速英语:Water Wheel Picks Up Trash in Baltimore's Waterways

2014-07-16来源:VOA

BALTIMORE — Trash in waterways around the world is a major environmental issue. The U.S. city of Baltimore, Maryland, is tackling its problem with a one-of-a-kind contraption with a water wheel that pulls in garbage. Since it began operating last May, the water wheel has proved more effective than other means of picking up trash in the water.

The odd-looking contraption sits on the Jones Falls River that flows into Baltimore's harbor. Every year, storm run-off from city streets carries huge amounts of garbage and debris into the river, polluting the harbor.

“After a rainstorm, we could get a lot of trash in Baltimore Harbor," said Adam Lindquist, who is with the Waterfront Partnership of Baltimore, the group that sponsors the water wheel. "Sometimes the trash was so bad it looked like you could walk across the harbor on nothing but trash.”

Water Wheel Picks Up Trash in Baltimore Waterways

Containment booms funnel trash and debris towards the gadget, where a leaf rake pulls it in and onto a moving conveyer that drops the garbage into a dumpster. The dumpster is on a floating dock that can be pulled to shore by boat, where the waste is burned to create electrical energy.

The water wheel is more efficient than the way the garbage was being picked up -- using small boats with nets.

Daniel Chase, co-designer of the device, says it can remove 45,000 metric tons of garbage each day.

“Instead of chasing one or two pieces of trash at a time, we just stand at the source of it and catch it all at once,” he said.

Chase says the garbage comes from people who throw litter like plastic bottles or Styrofoam plates on the ground, instead of putting it into bins.

The water wheel uses renewable energy -- mostly river current, but when needed, also energy from solar panels.

‘It is run on water, so it’s either river current, pushing from underneath or we are pumping water onto it which then fills buckets to carry the wheel around,” Chase said.

The rotation of the water wheel also provides other benefits by putting oxygen back into the river, and thus improving the water quality.

Chase says the technology can be used on waterways anywhere in the world. But he thinks that's not the answer in the long run.

“The real cure is not the water wheel. The real cure is not littering," he said. "And the best I can tell, that’s by educating children.”

Lindquist agrees.

“Our goal is actually to put the water wheel out of business," he said. "Of course, that will come through behavior change, if people don’t let garbage leave their hands except to go into a receptacle, then we wouldn’t need a water wheel.”

Lindquist says the water wheel is also helping with another goal -- to make the harbor safe for swimming by 2020.