A Novel Way to Clean Wastewater

Green: Science

Seven years ago, Paul Edmiston was working in his laboratory on a potential way to detect the presence of explosives. By accident, he created a material that acted as a powerful sponge that could absorb small organic compounds like gasoline, motor oil, and pesticides  dissolved in water.

Today Dr. Edmiston, a professor of chemistry at the College of Wooster in Ohio, is hoping that his invention, dubbed Osorb, will have a new commercial application:  cleaning the wastewater created by the drilling process called hydraulic fracturing.

In fracking, a mix of water, sand and chemical additives is injected into a drilling well under heavy pressure to release natural gas from shale deposits. At the end of the process, some of the chemical-laden water returns to the surface along with salts, radioactive elements and other contaminants absorbed from the shale. Safely disposing of the waste from fracking without contaminating drinking water and waterways has been a major environmental and health concern.

The overall safety of shale-gas drilling has been a contentious issue recently in Ohio: just last month, the state legislature passed a bill  imposing regulations on oil and gas drilling in the state amid criticism  that the rules had not been adequately discussed or debated.

Adding to concerns, the state Department of Natural Resources reported  in March that, as suspected, the injection of waste from oil and gas drilling  underground was probably the cause of several earthquakes in the Youngstown, Ohio, area.

Dr. Edmiston is gambling that  the swellable glass that he stumbled upon years ago could help address the wastewater challenge. “We’re offering a solution to a problem,” he says. “As a scientist, I’m saying, ‘Here’s a really good innovation that will help treat the waste.’ ”

Osorb is an organosilica material, “halfway between the silica in your window and the silicone in your tub,” he said. The porous substance adheres to itself, which keeps the material compressed. When it comes into contact with small molecules that can fit through its tiny pores, it expands to up to eight times its weight, Dr. Edmiston said.

The molecules that make up Osorb repel water so that it cannot absorb any, which could make it a powerful tool for cleaning water, he said.

In its original formulation, Dr. Edmiston said, Osorb was most useful for pulling dissolved oil out of water. Since then he and ABSMaterials[, the company that he founded in late 2008 to commercialize his discovery, have come up with about 30 different variations.

Two years ago, Dr. Edmiston and his team began adapting Osorb to prevent the flowback of the chemical additives that are used in fracking and the organic compounds that the water absorbs underground in a project financed by the federal government’s Small Business Innovation Research program.

By tweaking the molecules that form the material, changing their concentrations and controlling the rate of the chemical reaction that drives the material’s production, Dr. Edmiston has been able to remove more than 90 percent of the organic compounds found in the wastewater from fracking when it comes out of the ground.

So far  he  and his team have been able to treat some of the contaminants associated with flowback. Next they will  turn their attention to other substances in the wastewater like radioactive elements and rare earth metals, and scaling up the treatment system they have developed to clean the wastewater more quickly and at a lower cost.

Dr. Edmiston hopes that Osorb will be useful in mitigating the environmental impact of fracking as the drilling practice spreads.   “Unfortunately, we’re going to rely on hydrocarbon energy for a while,” he said.