Companies that drill for oil or natural gas using hydraulic drilling should consider recycling and reusing wastewater from wells. Chemistry students at The University of Toledo discovered many environmental contaminants, including organic chemicals and metal elements.
In collaboration with the University of Texas Arlington’s Dr. Nina McClelland Laborator for Water Chemistry, and Environmental Analysis, researchers at UToledo have performed a thorough analysis of the chemical makeup of Texas produced water samples. The results showed that untreated samples contained toxic and carcinogenic chemicals that could pose a threat to wildlife as well as human health.
The results of specialized extraction methods were used to unravel the complex composition of the water produced. Environmental Science and TechnologyProvide critical information that will help regulators fine-tune proposed guidelines for safe treatment and disposal fracking wastewater in order to protect drinking water sources.
“The discovery of these chemicals within the produced water suggests that more monitoring and remediation efforts will be needed since many of them have been listed as dangerous for human health” said Dr. Emanuela Gionfriddo assistant professor of analytical chemistry at the UToledo Department of Chemistry and Biochemistry and the School of Green Chemistry and Engineering. “Our detailed characterization gives insight into the hydraulic fracturing process and the nature geologic formations at each well site.”
Drilling operations often involve injecting treated water into subsurface. This water contains various publically disclosed additives that aid in the drilling process. The injected water reacts with groundwater and resurfaces in the form of a waste byproduct that contains contaminants from both the drilling site as well as the additives.
Gionfriddo’s research team developed an approach called thin-film-solid-phase microextraction in 2020. This method was used by the chemists to extract organic solvents from eight samples of water from the Permian basin and Eagle Ford formation in Texas.
Analyses revealed 266 different dissolved organic substances, including atrazine, a pesticide; 1,4-dioxane which is irritating to the eyes, respiratory tract, and liver; pyridine, which may damage the liver; as well as polycyclic aromatic hydrocarbons, (PAHs), that have been linked with skin, bladder, liver, stomach, and stomach cancers.
The team confirmed 29 elements using a new polymer that was developed at UToledo in 2021.
The researchers also recommend that the technology used in their detailed analysis of produced water is essential to ensure proper reuse or disposal for oil and gas producers.
Dr. Jon Kirchhoff, Distinguished Professor and Chair of the UToledo Department of Chemistry and Biochemistry, stated that they found a way to use more accessible instruments in the analysis of complex samples than more expensive workflows involving high resolution mass spectrometry.
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MaterialsProvided by University of Toledo. Original written by Christine Billau Note: Content can be edited for style or length.
