UC Irvine

The unconventional production of natural gas from shale resources has increased the total dry natural gas production in the United States. The increasing demand from industrial and electrical power markets will likely cause increase in U.S. natural gas consumption, leading to an increase in the volume of waste. There have been concerns regarding the effective management of the high salinity wastewaters that return to the surface, mainly due to the mobility and local accumulation of naturally occurring radioactive materials (NORMs), such as radium-226. Studies have found radium activity in shale produced wastewater well above federal limits. Current treatment strategies include temporary storage sites and wastewater treatment plants; however, concerns over public and worker exposure and environmental contamination has led to the exploration of other treatment technologies.

This project will explore previously established methods for water treatment and apply them to challenges that emerged due to advancements in oil and gas extraction technologies. Wastewaters from the Eagle Ford Shale formation in Texas were used as a platform for high salinity water samples. Various analytical techniques were explored to accurately determine the amount of radium-226, since the highly saline matrix complicate already established methods. The analysis of radium via electrodeposition and alpha spectrometry is a point of focus in this project because it allows quantitative determination of small quantities of material. However, separation steps are necessary to ensure the accuracy of this method. Ion exchange and solvent extraction studies coupled with crown ethers were carried out to separate radium and barium from other ions as well as from each other. Results showed high degrees of separation of radium and barium from other ions as well as from each other. The studies done here can help inform the management of environmental samples with high levels of NORM.