Researchers at the University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) are investing $200,000 in new research to develop a low-cost method to treat flow-back water following hydraulic fracturing, or fracking.
Over the next year, the researchers will use an inexpensive charcoal product called biochar for the water treatment method. It will be tested on water samples from the Eagle Ford Shale, UTSA and SwRI say.
Flow-back water treatment is currently a critical sustainability issue for the oil and gas industry. By sheer volume, flow-back water is expensive to treat because a single well can require 1 million to 5 million gallons of fracking fluid. Environmental factors also must be considered because flow-back water includes salts, hydrocarbons and heavy metals, making it unsafe for disposal on land and in streams.
UTSA mechanical engineering faculty member Zhigang Feng and SwRI senior research scientist Maoqi Feng believe that they can alter biochar derived from wood chips to create an economical and environmentally friendly solution. Produced from pyrolysis of biomass, biochar is a stable charcoal-like solid that attracts and retains water, absorbing impurities such as hydrocarbons, organics, biocides and certain inorganic metal ions.
Over the course of the study, the researchers will isolate, prepare and characterize the biochar; test the biochar on flow-back water samples from the Eagle Ford shale; develop computer models of the biochar water treatment system; and assess the biochar performance for possible improvements.
If successful, the researchers say they expect the biochar treatment to be the second step of a two-step water purification process. The first step would include filtration to remove the solids in the water remaining from the fracking process. The treated water would then be ready for re-use or safe disposal.
Global Industrial Water this week begin a 14-day trial to find a treatment or series of treatments whereby produced water from oil and gas operations can be rendered fit for agricultural, municipal and industrial use, as well as reuse in fracking.
Image Credit: University of Texas at San Antonio