UT College of Engineering News

Reverse osmosis seen as solution for toxin

GIBRALTAR ISLAND, Ohio — Through a new research project, a University of Toledo scientist believes he can show that reverse osmosis — a technology pioneered in the 1960s to take salt out of seawater — could likewise remove any algal toxins that get into tap water like they did for three days during the 2014 Toledo water crisis.

While many experts believe in the premise outlined by G. Glenn Lipscomb, professor and chairman of UT’s chemical and environmental engineering department, the theory still needs to be tested for under-sink reverse osmosis systems people can buy from home improvement stores for about $250. If validated, the research could strengthen the market for those devices and give homeowners a chance for more peace of mind.

“I guarantee you it will take out 99 percent of microcystin,” said Joseph Cotruvo, a former U.S. Environmental Protection Agency water division chief who spent years as an international water-treatment consultant and has been a member of a World Health Organization committee examining dangers of microcystin, Lake Erie’s chief algal toxin.

Mr. Lipscomb’s research, part of a $1.9 million Ohio Department of Higher Education award split among eight Ohio universities, is supported by Ann Arbor-based NSF International, which specializes in science for testing standards at water-treatment plants.

He said other partners include Dow Water & Process Solutions, a division of Dow Chemical, and the National University of Singapore, in collaboration with Singapore Public Utilities Board.

Some of the world’s top water research occurs in water-stressed Singapore.

During a recent presentation at Ohio State University’s Stone Laboratory on Gibraltar Island, near Put-in-Bay, Mr. Lipscomb said reverse osmosis technology came of age in the 1960s in parallel with desalination, the process by which salt is removed from seawater. The technology became much more fine-tuned about 1980, he said.

Reverse osmosis is a process that goes against the natural tendencies that solvent, water-based molecules have to mix together and equalize.

Instead, water is pushed hard — very hard — under pressure through a semi-permeable membrane so fine that it can filter out impurities down to the molecular level. The water on the other side that has been squeezed through the membrane is free of impurities.

The theory is algal toxins could be removed like salt particles, minerals, and other solids.

“It’s to provide the public with that certainty,” Mr. Lipscomb said of his research project.

There are at least two downsides: Reverse osmosis is incredibly energy-intensive because of the amount of pressure required. And there can be as much or more wastewater generated as good water from the technique.

In industrial uses, some minerals actually have to be added back in to stabilize water that has gone through a reverse osmosis treatment; otherwise, it would corrode pipes.

For those reasons, experts such as Mr. Cotruvo, while highly interested in what Mr. Lipscomb finds out, wonder how practical it would be for average homeowners.

Mr. Lipscomb said he doesn’t have a treatment system at his home.

“There’s nothing wrong with Toledo water now,” he said.

But he said his research offers promise if western Lake Erie’s chronic algae problem worsens, something which has happened in recent years.

After 20 years with little or no algae, microcystis — one of the main producers of microcystin — began appearing annually in western Lake Erie again in 1995. Records show it has come on stronger since 2002, with a record bloom recorded in 2011.

National Oceanic and Atmospheric Administration scientists were so confident that was the worst it would get they used that bloom as the end point for a predictive forecasting model they developed on a 1 to 10 scale, with 2011 being the 10.

The 2015 bloom smashed that record, setting the bar higher.

This year has been far different. Much like 2012, drought conditions have limited runoff and resulted in a lot less algae.

But microcystis — one of Earth’s oldest-living organisms at 3.5 billions years old — has been on the rise globally the last 20 years for reasons scientists don’t fully understand. It wasn’t even Lake Erie’s dominant algae when the lake began to heal following passage of the federal Clean Water Act of 1972, which ushered in the modern era of sewage treatment.

Many experts believe, though, that climate change and poor land use mean this region and others will be battling algae for years to come.

A blue ribbon committee formed in response to the 2014 water crisis never priced the cost of installing reverse osmosis in Toledo’s aging Collins Park Water Treatment Plant because it didn’t seem to be a good match for the city, not just because of expenses but also because of the way that plant is designed, Andy McClure, Collins Park Water Treatment Plant superintendent, said.

“To the blue ribbon panel, it was obvious. It was impractical,” Mr. McClure said. “It could be corrosive and is very energy intensive…. It never really did an estimate of it.”

Instead, the city is spending millions of dollars to modernize and expand the plant in other ways. One of the cornerstones of that work, approved by the Ohio Environmental Protection Agency, is to use ozone treatment as a finishing process to remove more impurities while also improving taste and reducing odors.

One of America’s largest water-treatment plants using reverse osmosis is a Southern California plant operated by the Orange County Water District, which processes 100 million gallons of water a day for nearly 850,000 Orange County residents.

Other large ones are in Florida.

Toledo processes up to 120 million gallons a day for about 500,000 metro area residents.

By comparison, the world’s largest desalination plant is the Sorek plant in Israel, near Tel Aviv, which processes 150 million gallons a day.

Bowling Green installed reverse osmosis system at its much smaller water-treatment plant in 2011.

The Bowling Green plant — built in 1950 and expanded in 1968 — has an average capacity of 7.2 million gallons a day, but is rated to produce up to 11 million gallons a day.

Mike Fields, assistant Bowling Green water superintendent, said reverse osmosis was installed to remove potentially dangerous chlorine byproducts known as trihalomethanes.

Toledo removes its with a different process.

He said it “takes a lot of electricity” to push water through the reverse osmosis system.

For a facility as big as Toledo’s, ozone makes sense, Mr. Fields said.

“The wave of the future — if you’re talking about toxins, it’s probably ozone,” he said. “It depends on the plant.”

Mr. Lipscomb believes the future is in reverse osmosis, especially if costs and logistics can be worked out.

“My guess is that as this treatment gets affordable, it will be in more water-treatment plants,” Mr. Lipscomb said. “To me, this technology solves all problems we’re concerned with with water.”

He said it’s “going to require convincing the public this is a long-term investment they need.”

“It’s like switching over from fossil fuels to renewables,” Mr. Lipscomb said.

Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.

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