Researchers test bleach, vitamin C combination for ballast cleanup

Dave Hand has a plan to eliminate invasive species in ships' ballast water that is as simple as laundry bleach and vitamin C.

Hand wants to treat ballast water with sodium hypochlorite (aka laundry bleach) and then, when all the bad critters in the ballast tanks are dead, neutralize the bleach with ascorbic acid (aka vitamin C).

It's the same basic principle that sewage treatment plants have used for decades to treat wastewater.

So why not use it on ships, asks Hand, a professor of civil and environmental engineering at Michigan Technological University.

Hand's simple idea is being tested this month by researchers with the Great Ships Initiative in Superior -- a collaborative of university scientists that is funded by the federal government and operated by the American Great Lakes Ports Association and the Northeast-Midwest Institute.

If it passes muster in laboratory tests at the University of Wisconsin-Superior, the treatment may be tested in the full-scale, dockside facility in Superior that mimics a ships ballast water system.

Hand said service boats could deliver the bleach -- about 70 gallons for a 1,000-foot ore carrier, for example, and about the same amount of vitamin C -- to the boat or ship when it arrives in port.

The bleach could be poured into ballast tanks before ballast water is taken on for loading balance. He said the bleach would kill everything in the tanks in about the time it takes a 1,000-footer to cross Lake Superior.

Then, the vitamin C would be added to neutralize the bleach during the rest of the trip.

By the time the 1,000-footer arrived at its destination, the bleach would be rendered harmless, and the ballast water would be discharged.

Scientists in the programsaid the tests in Superior willuse a water flea, a copepod, a rotifer and rotifer cyst to test the effectiveness of bleach. The same critters are used for all tests through Great Ships.

Some shipping interests said the bleach/vitamin C wouldn't work, but Hand and officials from Isle Royale National Park last year proved it could work on Lake Superior. The park has been using bleach followed by vitamin C successfully since last fall to treat ballast in the park service's 165-foot passenger ferry, the Ranger III.

"It's doing what we hoped it would. It's an effective emergency effort until we find a permanent solution," said Phyllis Green, superintendant of Isle Royale National Park. "We're dosing at levels that kill VHS, and the water we release meets clean water standards. I'm hoping we can pass this on for other people to use. ... There's no reason to wait for the perfect solution that may never come."

Hand sees the bleach/vitamin C solution as a temporary fix until permanent ballast treatment can be installed on all saltwater and Great Lakes ships. While the released water is, in theory, benign to the environment, Hand said a system that uses no chemicals would be better for a permanent fix. That could include UV light, agitation, filters, heat or other measures.

"I got a lot of negative feedback from some shipping people on this last idea fall" at a conference in Duluth, Hand said. "But I'm trying to do them a favor. This is going to be a good emergency ballast treatment system that can be used for three or four years until a permanent solution is ready. ... And who knows, maybe it ends up as the cheapest and the best long-term solution, too."