title: Naphthenic acids speciation and removal during petroleum-coke adsorption and ozonation of oil sands process-affected water.
abstract: The Athabasca Oil Sands industry produces large volumes of oil sands process-affected water (OSPW) as a result of bitumen extraction and upgrading processes. Constituents of OSPW include chloride, naphthenic acids (NAs), aromatic hydrocarbons, and trace heavy metals, among other inorganic and organic compounds. To address the environmental issues associated with the recycling and/or safe return of OSPW into the environment, water treatment technologies are required. This study examined, for the first time, the impacts of pretreatment steps, including filtration and petroleum-coke adsorption, on ozonation requirements and performance. The effect of the initial OSPW pH on treatment performance, and the evolution of ozonation and its impact on OSPW toxicity and biodegradability were also examined. The degradation of more than 76% of total acid-extractable organics was achieved using a semi-batch ozonation system at a utilized ozone dose of 150 mg/L. With a utilized ozone dose of 100 mg/L, the treated OSPW became more biodegradable and showed no toxicity towards Vibrio fischeri. Changes in the NA profiles in terms of carbon number and number of rings were observed after ozonation. The filtration of the OSPW did not improve the ozonation performance. Petroleum-coke adsorption was found to be effective in reducing total acid-extractable organics by a 91%, NA content by an 84%, and OSPW toxicity from 4.3 to 1.1 toxicity units. The results of this study indicate that the combination of petroleum-coke adsorption and ozonation is a promising treatment approach to treat OSPW.
authors: Department of Civil and Environmental Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2W2. mgamalel-din@ualberta.ca
authors: Mohamed
authors: M
authors: Gamal El-Din
authors: Hongjing
authors: H
authors: Fu
authors: Nan
authors: N
authors: Wang
authors: Pamela
authors: P
authors: Chelme-Ayala
authors: Leonidas
authors: L
authors: Pérez-Estrada
authors: Przemysław
authors: P
authors: Drzewicz
authors: Jonathan W
authors: JW
authors: Martin
authors: Warren
authors: W
authors: Zubot
authors: Daniel W
authors: DW
authors: Smith
mesh_terms: D000327:Adsorption; D000416:Alberta; D002264:Carboxylic Acids / Q000737:chemistry*; D003077:Coke; D019652:Extraction and Processing Industry; D005374:Filtration; D006838:Hydrocarbons; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010126:Ozone; D010578:Petroleum; D014733:Vibrio / Q000187:drug effects; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D002264:Carboxylic Acids; D003077:Coke; D006838:Hydrocarbons; D010083:Oxidants, Photochemical; D010578:Petroleum; D014874:Water Pollutants, Chemical; D010126:Ozone; C006647:asphalt; C046170:naphthenic acid