title: Removal of organic compounds and trace metals from oil sands process-affected water using zero valent iron enhanced by petroleum coke.
abstract: The oil production generates large volumes of oil sands process-affected water (OSPW), referring to the water that has been in contact with oil sands or released from tailings deposits. There are concerns about the environmental impacts of the release of OSPW because of its toxicity. Zero valent iron alone (ZVI) and in combination with petroleum coke (CZVI) were investigated as environmentally friendly treatment processes for the removal of naphthenic acids (NAs), acid-extractable fraction (AEF), fluorophore organic compounds, and trace metals from OSPW. While the application of 25 g/L ZVI to OSPW resulted in 58.4% removal of NAs in the presence of oxygen, the addition of 25 g petroleum coke (PC) as an electron conductor enhanced the NAs removal up to 90.9%. The increase in ZVI concentration enhanced the removals of NAs, AEF, and fluorophore compounds from OSPW. It was suggested that the electrons generated from the oxidation of ZVI were transferred to oxygen, resulting in the production of hydroxyl radicals and oxidation of NAs. When OSPW was de-oxygenated, the NAs removal decreased to 17.5% and 65.4% during treatment with ZVI and CZVI, respectively. The removal of metals in ZVI samples was similar to that obtained during CZVI treatment. Although an increase in ZVI concentration did not enhance the removal of metals, their concentrations effectively decreased at all ZVI loadings. The Microtox(®) bioassay with Vibrio fischeri showed a decrease in the toxicity of ZVI- and CZVI-treated OSPW. The results obtained in this study showed that the application of ZVI in combination with PC is a promising technology for OSPW treatment.
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Parastoo
authors.initials: P
authors.lastname: Pourrezaei
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Alla
authors.initials: A
authors.lastname: Alpatova
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Kambiz
authors.initials: K
authors.lastname: Khosravi
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Drzewicz
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2.
authors.forename: Pamela
authors.initials: P
authors.lastname: Chelme-Ayala
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2. Electronic address: mgamalel-din@ualberta.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Gamal El-Din
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D002264:Carboxylic Acids / Q000737:chemistry / Q000633:toxicity; D003077:Coke; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry* / Q000633:toxicity; D008670:Metals / Q000737:chemistry / Q000633:toxicity; D061329:Oil and Gas Fields; D010578:Petroleum; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity
chemical_list: D002264:Carboxylic Acids; D003077:Coke; D007220:Industrial Waste; D008670:Metals; D010578:Petroleum; D014874:Water Pollutants, Chemical; D007501:Iron; C046170:naphthenic acid
keywords: Adsorption; Oil sands process-affected water; Oxidation; Petroleum coke; Zero valent iron