Research helps power plants recycle water using wastewater from oil and gas mining

Simulations from West Virginia University researchers demonstrate their use of two kinds of industrial wastewater

Simulations from West Virginia University researchers demonstrate their use of two kinds of industrial wastewater to decontaminate each other has the potential to slash a power plant’s total water use.

The researchers from the WVU Benjamin M. Statler College of Engineering and Mineral Resources modeled various scenarios for using “cooling tower blowdown” and “produced water” to treat each other. Cooling tower blowdown is wastewater produced by thermoelectric power plants, while water is produced by hydraulic fracturing mining for oil and gas.

The cotreatment process yields valuable byproducts as well as water that’s clean enough to be reused in power plant cooling operations. The study’s findings were published in the journal Desalination.

According to lead author Hunter Barber, a doctoral student in chemical engineering from Fairchance, Pennsylvania, no other industry in the U.S. uses as much water as thermoelectric power generation.

“Our cotreatment process reduces demand for chemicals to soften wastewater,” Barber said. “The treated water also has very high potential for reuse—treated water can be directly reused after cotreatment to make up 99% to 100% of the original volume of blowdown water, and that’s without optimizing or exploring different designs.”

Presently, power plants draw fresh water from a surface water or groundwater source, run it through the cycle to generate steam and electricity, then minimally treat it and discharge it back to the surface or groundwater.

“Our approach is looking to close that cycle,” Barber said. “Instead of discharging the water, we treat it, and instead of drawing from fresh water, we recycle treated water back through.”

They’re reducing the amount of purifying chemicals needed to treat the power plant’s cooling blowdown with produced water, the oil and gas industry’s largest wastewater byproduct by volume. One current method for dealing with produced water from fracking is to inject it right back into the earth.