EPA Advances Process to Remove Metals From Water

EPA Advances Process to Remove Metals From Water

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To protect our nation's water supply from harmful industrial contaminants, the Environmental Protection Agency (EPA) has been significantly tightening limits for mercury and arsenic. At the same time, the EPA's Office of Research and Development is partnering with industry to develop technologies that help meet those standards.

The EPA's National Risk Management Research Laboratory in Cincinnati played a major role in developing a new material that can quickly, efficiently, and economically strip mercury and arsenic from industrial wastewater streams. Technology developed in the laboratory was licensed to a startup company, which manufactures the product and sells it to refineries, chemical manufacturers, power plants, mining companies and other industries.

"This is a great example of how EPA is not only involved in establishing the regulations, but is also helping companies meet them," said Dr. Michael Gonzalez, a chemist who was the project's chief investigator.

The story began several years ago when Metaloy, a recycler of waste materials from the petrochemical industry, was searching for ways to reuse the spent catalyst from a process that removes sulfur from crude oil. The spent catalyst had been used as concrete filler and to line road beds, but Metaloy asked the EPA laboratory whether it might have a better use.

Remembering lessons from a college biochemistry class, Gonzalez had the idea that the material might be able to strip metals from water. Tests confirmed that, showing the substance's ability to remove mercury and arsenic.

To pursue the research further, Metaloy spun off a new company, MAR Systems, and entered into a Cooperative Research and Development Agreement (CRADA) with the laboratory. Because the spent catalyst was not of consistent quality for commercial use, and was not being produced in sufficient quantities, MAR Systems and the EPA focused on reengineering the chemistry behind the catalyst to create an entirely new material.

The laboratory conducted a number of tests and experiments to determine what part of the spent catalyst was responsible for removing the metals.

"Basically, we wanted to know what made it work," Gonzalez said. "The idea was to break down the technology to understand it, and then build it back up to create a much more efficient material."

Using scanning electron microscopy and other analytical techniques, the EPA determined the active chemistry in the spent catalyst, and the technology was licensed exclusively to MAR Systems. With that information, the company created Sorbsterª, which is now being widely marketed.

According to Missy Hayes, Director of Business Development and Product Marketing for MAR Systems, "The laboratory gave us the ingredients, and we created the recipe to make it work."

Compared with other materials, Sorbsterª removes metals faster and more efficiently, and is more cost-effective, said Gonzalez.

In addition to mercury and arsenic, Sorbsterª has been developed to remove a number of other metals and ions from water, including selenium, hexavalent chromium and fluorides.

"We're meeting the needs of companies that don't have other choices," Hayes said. "Because our product is so inexpensive and easy to use, it helps companies solve the conflict between industry and the environment."

In 2010, Businessweek named MAR Systems to its list of "America's Most Promising Startups."

Sorbsterª has the consistency of fish-tank gravel and is sold by the pound. When it is placed in water filtration vessels, it removes metal contaminants in seconds. It does not leach the adsorbed contaminants over time, and thus can be disposed of conventionally, rather than as a hazardous material.

The laboratory continues to collaborate with MAR Systems through the CRADA as the company explores other commercial uses for Sorbsterª, including its potential to remove metals present in air emissions and groundwater.

"Through this CRADA, I can work with a company to solve real-world problems and have a positive impact on the environment," said Gonzalez. "That's my reward."