ATHENS, Ohio -- Researchers at Ohio University have invented a mechanical device that controls zebra mussels by lowering the oxygen level in water. In field tests of the apparatus at a water treatment facility in a Cleveland suburb, the scientists found that zebra mussels were unable to attach to pipes in this oxygen-controlled environment.
Since the tiny mollusk was first discovered in the United States in 1988, it has clogged water intake pipes in many cities along the Great Lakes and the Ohio and Mississippi rivers. Until now, chemicals have been used to control zebra mussel infestations, but installing chemical treatment systems is environmentally undesirable, and the added cost of the systems typically leads to higher water utilities for consumers.
The new device could control zebra mussels in an environmentally safe way at a significant savings to industry and consumers, said Tiao Chang, inventor of the device and professor of civil engineering in the Russ College of Engineering and Technology at Ohio University.
"The device can control zebra mussels in environments where they present a problem," such as in enclosed water conduits, ballast tanks in ships, or in water supplies used as coolants in power plants, he said. The device is not designed to eliminate zebra mussels, but can control the mussels in targeted areas.
Chang's device uses commercially available vacuum systems and unique chambers designed by Chang for the control of the dissolved oxygen level in water. When water passes through the chamber, the oxygen level is reduced, slowing the activity of any zebra mussels that may be present. Without sufficient oxygen, the mussels will not attach to surfaces of water conduits and form troublesome blockages.
Chang tested the invention at a water treatment facility that services many of the 150,000 residents of Avon Lake, located along Lake Erie just outside Cleveland. Since testing began in September, no zebra mussels have been detected.
During the tests, the scientists processed 13,000 gallons of water a day through Chang's device. But by applying the technology and using a larger chamber, more water could be delivered, Chang said.
One immediate use for the device could be to help the shipping industry eliminate zebra mussels from the ballast tanks of ships.
"Many people believe zebra mussels were introduced to our waters by ballast water in ships traveling from Europe," Chang said. "Our device is portable, so it could be installed on large ships to control zebra mussels and other aquatic nuisance species in the ballast tanks, preventing the further infestation of the waterways." Chang and Ohio University received a patent on the method to control zebra mussels in 1994. In November, the researcher and university received a patent on the actual device.
Chang and Ohio University received a patent on the method to control zebra mussels in 1994. In November, the researcher and university received a patent on the actual device.
The research findings were included as a special chapter in Zebra Mussels and Aquatic Nuisance Species, published recently by Ann Arbor Press Inc.
Contact: Tiao Chang, 614-593-1462; tjchang@bobcat.ent.ohiou.edu Written by Kelli Whitlock, 614-593-0383; kwhitlock1@ohiou.edu