Fugitive emissions of polycyclic aromatic compounds from an oil sands tailings pond based on fugacity and inverse dispersion flux calculations

Maryam Moradi; Yuan You; Hayley Hung; James Li; Richard Park; Nick Alexandrou; Samar G Moussa; Liisa Jantunen; Rachelle Robitaille; Ralf M Staebler

doi:10.1016/j.envpol.2020.116115

Fugitive emissions of polycyclic aromatic compounds from an oil sands tailings pond based on fugacity and inverse dispersion flux calculations

Environ Pollut. 2021 Jan 15:269:116115. doi: 10.1016/j.envpol.2020.116115. Epub 2020 Nov 23.

Authors

Affiliations

¹ Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, ON, M3H 5T4, Canada; Civil Engineering Department, Ryerson University, Toronto, ON, M5B 2K3, Canada.
² Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, ON, M3H 5T4, Canada.
³ Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, ON, M3H 5T4, Canada. Electronic address: hayley.hung@canada.ca.
⁴ Civil Engineering Department, Ryerson University, Toronto, ON, M5B 2K3, Canada.
⁵ Air Quality Processes Research Section, Environment and Climate Change Canada, 6842 Eighth Line, Egbert Ontario, L0L 1N0, Canada.

PMID: 33279269
DOI: 10.1016/j.envpol.2020.116115

Abstract

Alberta's oil sands tailings ponds are suspected to be a source of fugitive emissions of polycyclic aromatic compounds (PACs) to the atmosphere. Here we report, for the first time, fluxes of 6 parent and 21 alkylated PACs based on the measured co-located air and water concentrations using a two-film fugacity-based model (FUG), an inverse dispersion model (DISP) and a simple box model (BOX). Air samples were collected at the Suncor Tailings Pond 2/3 using a high volume air sampler from the "pond" and towards the pond ("non-pond") directions separately. Mean ∑₂₇PACs in air from the "pond" direction was greater than the "non-pond" direction by a factor of 17. Water-air fugacity ratio of 20 PACs quantifiable in water indicated net volatilization from water. Dispersion and box model results also indicated upward fluxes of 22 PACs. Correlation between the estimated flux results of BOX and DISP model was statistically significant (r = 0.99 and p < 0.05), and correlation between FUG and DISP results ranged from 0.54 to 0.85. In this first-ever assessment of PAC fluxes from tailings pond, the three models confirmed volatilization fluxes of PACs indicating Suncor Tailings Pond 2/3 is a source of PAC emissions to the atmosphere. This study addressed a key data gap identified in the Joint Oil Sands Monitoring Emissions Inventory Compilation Report (Government of Alberta and Canada, 2016) which is the lack of consistent real-world tailings pond fugitive emission monitoring of organic chemicals. Our findings highlight the need for measurements from other tailings ponds to determine their overall contribution in releasing PACs to the atmosphere. This paper presents a practical method for estimating PAC emissions from other tailings ponds, which can provide a better understanding of these fugitive emissions, and thereby help to improve the overall characterization of emissions in the oil sands region.

Keywords: Flux; High volume air sampler; Oil sands; Polycyclic aromatic compounds; Tailings ponds.

MeSH terms

Alberta
Oil and Gas Fields
Organic Chemicals
Polycyclic Compounds*
Ponds*

Substances

Organic Chemicals
Polycyclic Compounds