Engineers at the University of Colorado Boulder have invented a process that can simultaneously remove both salts and organic contaminants from wastewater that comes from oil and gas operations while producing additional energy.
The new treatment technology, called microbial capacitive desalination, is similar to a battery in its basic form, but instead of using chemicals to generate the electrical current as in a traditional battery, the process uses microbes to generate an electrical current that can then be used for desalination.
This microbial electrochemical approach takes advantage of the fact that the contaminants found in the wastewater contain energy-rich hydrocarbons, the same compounds that make up oil and natural gas. The microbes used in the treatment process eat the hydrocarbons and release their embedded energy. The energy is then used to create a positively charged electrode on one side of the cell and a negatively charged electrode on the other, essentially setting up a battery. The additional energy can be used on-site to run equipment, according to the researchers.
The process offers the possibility water for fracking — expensive and increasingly difficult to find — can be more economically treated on site and reused in the fracking process.
To try to turn the technology into a commercial reality, Ren and Forrestal have co-founded a startup company called BioElectric.
The new technique was recently covered in an article published in the journal Environmental Science Water Research & Technology. Zhiyong Jason Ren, a CU-Boulder associate professor of environmental and sustainability engineering, is senior author of the paper. Casey Forrestal, a CU-Boulder postdoctoral researcher, is lead author of the paper and is working to commercialize the technology.