Fracking water reuse economised
21 Oct 2014
Scientists use established technology to purify and reuse water taken from hydraulic fracturing (fracking) wells, a new report suggests.
A team of researchers from the Massachusetts Institute of Technology (MIT) and Saudi Arabia has developed a cost-effective solution that removes much of the salt deposited in the water used within the fracking process.
Through electrodialysis, a process which is designed to transport salt ions from one solution through ion-exchange membranes to a second solution by means of an applied electric potential difference, salt found in fracking water can be efficiently removed and the water reused in subsequent fracking wells.
“Electrodialysis is generally thought of as being advantageous for relatively low-salinity water such as the brackish, shallow groundwater found in many locations, generally with salinity around one-tenth that of seawater,” said John Lienhard, MIT professor and the paper’s co-author.
“But electrodialysis also turns out to be economically viable at the other end of the salinity spectrum, the new analysis shows,” Lienhard said.
The researchers do not intend to purify fracking water to make in fit for human consumption as electrodialysis becomes less and less efficient as the water gets less saline.
Instead, the water would be purified enough to reuse as part of the hydraulic fracturing fluid injected into a variety of wells - a process which would significantly reduce the need for water that has been diverted from other sources.
Following successful salinity and filtration testing, the research team hopes to dramatically reduce the need for fresh water use within the fracking industry - especially in oil-producing regions of the US such as Texas, which researchers claim is currently experiencing water scarcity.
