title: Spills of Hydraulic Fracturing Chemicals on Agricultural Topsoil: Biodegradation, Sorption, and Co-contaminant Interactions.
abstract: Hydraulic fracturing frequently occurs on agricultural land. Yet the extent of sorption, transformation, and interactions among the numerous organic frac fluid and oil and gas wastewater constituents upon environmental release is hardly known. Thus, this study aims to advance our current understanding of processes that control the environmental fate and toxicity of commonly used hydraulic fracturing chemicals. Poly(ethylene glycol) surfactants were completely biodegraded in agricultural topsoil within 42-71 days, but their transformation was impeded in the presence of the biocide glutaraldehyde and was completely inhibited by salt at concentrations typical for oil and gas wastewater. At the same time, aqueous glutaraldehyde concentrations decreased due to sorption to soil and were completely biodegraded within 33-57 days. While no aqueous removal of polyacrylamide friction reducer was observed over a period of 6 months, it cross-linked with glutaraldehyde, further lowering the biocide's aqueous concentration. These findings highlight the necessity to consider co-contaminant effects when we evaluate the risk of frac fluid additives and oil and gas wastewater constituents in agricultural soils in order to fully understand their human health impacts, likelihood for crop uptake, and potential for groundwater contamination.
authors.affiliation: Department of Civil and Environmental Engineering, Colorado State University , 1320 Campus Delivery, Fort Collins, Colorado 80523, United States.
authors.forename: Molly C
authors.initials: MC
authors.lastname: McLaughlin
authors.affiliation: Department of Civil and Environmental Engineering, Colorado State University , 1320 Campus Delivery, Fort Collins, Colorado 80523, United States.|Department of Chemistry, Colorado State University , 1872 Campus Delivery, Fort Collins, Colorado 80523, United States.|Department of Soil and Crop Sciences, Colorado State University , 1170 Campus Delivery, Fort Collins, Colorado 80523, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Borch
authors.affiliation: Department of Civil and Environmental Engineering, Colorado State University , 1320 Campus Delivery, Fort Collins, Colorado 80523, United States.
authors.forename: Jens
authors.initials: J
authors.lastname: Blotevogel
mesh_terms: D000383:Agriculture; D001673:Biodegradation, Environmental; D060587:Groundwater; D006801:Humans; D000067071:Hydraulic Fracking; D062065:Wastewater
chemical_list: D062065:Wastewater