Work

Mesocosm Study of Chemical Treatments on Methane Emissions in Oil Sands Tailings Ponds – Part II: Illustrating the Relationship of Naphthenic Acids with Methanogenesis

Year: 2026

Type: article

Abstract: Naphthenic acid fraction compounds (NAFCs) are primary toxic components in oil sands process-affected water. Chemical treatments in tailings ponds can influence their concentration and composition, which may affect their toxicity. It is therefore crucial to measure the levels and distribution of NAFCs if there is any chemical treatment process being implemented in the tailings ponds. In the literature, some potential chemical treatment processes have shown promising results in terms of methane inhibition, thus reducing fugitive greenhouse gas (GHG) emissions from tailings ponds. However, little has been established to date on how the methanogenesis process along with chemicals used in the treatment affects the concentration and compositional characteristics of the NAFCs in the tailings ponds. In this study, laboratory scale bottle tests simulating oil sands tailings pond environments were used to investigate joint outcomes of chemical treatments on methanogenesis in relation to the concentrations and molecular level characteristics of NAFCs. Among the four chemicals (Na2MoO4·2H2O, Fe2(SO4)3, Na2SO4, and Na3C6H5O7·2H2O) tested, Fe2(SO4)3 reduced both methane production and the concentration of the NAFCs. There was also evidence for oxidative transformation of classical naphthenic acids (i.e., O2-NAFCs) presented in the study. These findings suggest the potential of using Fe2(SO4)3 as a chemical amendment for NAFC attenuation and methane reduction to assist with the cleanup effort for oil sands tailings ponds.

Source: ACS Omega

DOI: 10.1021/acsomega.5c09941

Authors: Xiaomeng Wang, Ian Vander Meulen, Dena W. McMartin, Chukwuemeka Ajaero, John Headley, Bipro Ranjan Dhar

Institutions: Natural Resources Canada, Environment and Climate Change Canada, University of Lethbridge, University of Alberta

Language: English

Topic: Mine drainage and remediation techniques

Subfield: Environmental Chemistry

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: Government of Canada, Office of Energy Research and Development