Wealth of natural gas fuels toxic waste research at Pitt

Pitt researchers have received a federal grant for managing the toxic waste that might be caused… Pitt researchers have received a federal grant for managing the toxic waste that might be caused by accessing a gas reserve — a project that could be worth trillions of dollars.

Located under parts of Pennsylvania, Ohio, West Virginia and New York, the Marcellus Shale formation contains such a large amount of natural gas that, if extracted and sold, it could potentially be worth trillions of dollars, said Radisav Vidic, professor and chair of Pitt’s department of civil and environmental engineering.

Tapping this gas reserve could lead to serious environmental and health hazards for people in nearby communities, Vidic said. But he and other Pitt researchers are working on a $1.06 million federal project funded by the U.S. Department of Energy to better manage the wastewater that comes with extracting gas in the Marcellus Shale.

Vidic, who has done research at Pitt since 1992, said the project gives the University a chance to make an impact.

“It’s very challenging, but it gives us the opportunity to do something really meaningful for the state and industry,” Vidic said. “Hopefully, we will see it applied in the field and make a difference in the economic development.”

Heading the three-year project with Eric Beckman, co-director of Pitt’s Mascaro Center for Sustainable Innovation and the George M. Bevier professor of chemical and petroleum engineering, Vidic said that the researchers will focus on how to reuse this wastewater while reducing the level of treatment it requires before being reused.

The natural gas that is available in the Marcellus Shale is absorbed in a tightly-packed layer of soil that must be fractured in order to allow the gas to escape, said Vidic. To fracture the rock, workers must drill a 6,000-foot well before injecting a high-pressure mix of local-source freshwater, sand and chemicals called “slicking agents.”

The sand from the mixture gets shoved into the shale to keep it open while the gas travels out of it, he said. But after injecting 2 to 5 million gallons of the water-sand mixture, the water needs to get out of the shale to allow the gas to escape into the well.

Between 30 to 80 percent of the water comes back and contains so much waste that it can have five to six times more salt than seawater, he said. This wastewater contains hydrocarbons, heavy metals, natural radioactive materials and very high levels of total dissolved solids, which could end up in surface water and put local residents at risk.

To solve this problem, Vidic said that Pitt researchers plan to develop a way to reuse this wastewater for fracturing the adjacent walls.

To do this, they need to develop new slicking agents that will work with the highly salty water and to design chemicals that will allow them to reuse the water, no matter how contaminated it might be. Vidic said his team also hopes to find a way to use acid mine drainage as a sanitizer and supplemental water source.

The first phase of the project will allow researchers to understand the chemistry of the wastewater, as well as how it reacts with acid mine drainage. After completing studies and inventories on the water in the Marcellus Shale, researchers will design and make new slicking agents in the laboratory.

They will then test the agent under lab conditions before designing a treatment process, finding a suitable site to run a test treatment and eventually learning what it will cost to conduct a large-scale treatment process.

“It’s a lot of pressure because everyone’s looking at us and wondering how we’re going to do it,” Vidic said. “It’s also a very real economical opportunity, so a lot of companies are trying to get in on the game.”

Although Vidic said that he has conducted research for about 20 years, he admitted that this project has been one of the most exciting ones that he has worked on over the course of his career.

“We’re under a little bit of scrutiny and pressure, but it’s what we’re made to do as researchers,” he said. “We solve problems.”