Investigating graphene oxide permeable reactive barriers for filtering groundwater contaminated from hydraulic fracturing

Hydraulic fracturing, or fracking, is a method of natural gas extraction which involves pumping a brine solution into the ground to create a fracture that will allow natural gas to rise. One of the major concerns surrounding this method of natural gas extraction is that wastewater enters the groundwater supply, thereby contaminating it. This wastewater contains toxic materials such as heavy metal ions, radionuclides and other salts and organic compounds in high concentrations. Some of these materials are carcinogenic and thus a concern to human life and the environment. The current solution involves the use of a zerovalent iron (ZVI) permeable reactive barrier (PRB) to filter out these toxic substances. However, it causes more fouling due to the accumulation of mineral precipitates and therefore is not very effective. A recent development in nanotechnology may allow us to develop a superior water filter to prevent groundwater contamination. Therefore, a novel PRB is suggested: featuring the use of solid graphene oxide (GO), a nanomaterial with a superior sorption ability is proposed as a replacement for the system. The proposed experiment will test the filtration capability of the GO-PRB as compared to the traditional ZVI-PRB. By emulating the process of groundwater contamination and flow using common materials found in fracking wastewater, we can determine how much more effective the GO-PRB is than the ZVIPRB.