Abstract: The oil sands industry produces large volumes of oil sands process-affected water (OSPW) as a result of bitumen extraction and upgrading processes. OSPW is the water contained in tailings impoundment structures in oil sands operations. There are concerns about the environmental impacts of the release of OSPW because of its toxicity. OSPW has been reported to cause both acute and chronic toxicity to a variety of organisms, including fish, amphibians, phytoplankton, and mammals. OSPW is a very complex mixture of suspended solids, salts, inorganic compounds, dissolved organic compounds, and trace metals. Currently, OSPW is retained on site and there is no active return to the regional watershed. Although efforts have been made to assess individual water treatment processes to remove or degrade specific constituent(s) of OSPW, a strategy to treat and manage the various streams of OSPW has not been proposed so far. There is an urgent need for research to find different approaches and strategies for OSPW treatment and management.
Advanced Oxidation Processes (AOPs) are intended to oxidize organic and inorganic compounds by generating powerful oxidants such as hydroxyl radicals. AOPs, including ozonation, ultraviolet light (UV) combined with hydrogen peroxide (H2O2), and vacuum UV, among others, are being used as treatment alternatives, at laboratory-scale, to accelerate the decontamination and detoxification of OSPW. Moreover, ozonation and AOPs are being used as pre-treatment steps in order to convert initially persistent organic compounds in OSPW such as naphthenic acids (NAs) into more biodegradable intermediates, which can be treated using biological processes, among others. The results have shown that NAs with more rings and more carbon atoms are degraded more rapidly during the ozonation process. It has also been found that NAs with more carbon atoms are favoured for degradation when using UV/H2O2. However, increasing the number of rings (or double bond equivalents) in NAs does not show any clear structure reactivity during UV/H2O2 treatment. It has been found that the principal byproducts formed during hydroxyl-radical-induced decomposition of cyclohehanoic acid (CHA), a model NAs compound, are hydroxy-CHA, dihydroxy-CHA, and oxo-CHA. This presentation is designed to bring forward the recent advances of ozonation and AOPs in terms of process fundamentals, oxidation mechanism, and byproduct formation when applied to the treatment of OSPW.
Bio: Dr. Gamal El-Din is presently a Professor in the Department of Civil and Environmental Engineering at the University of Alberta. He is also an Adjunct Professor in the Department of Public Health Sciences, School of Public Health at the University of Alberta. Dr. Gamal El-Din is the lead on the Helmholtz-Alberta Initiative (HAI) Theme 5 on Oil Sands Tailings Water Management. In July 2011, Dr. Gamal El-Din started an NSERC Senior Industrial Research Chair Program on Oil Sands Tailings Water Treatment.
Dr. Gamal El-Din earned his Bachelor’s Degree in Civil Engineering from Cairo University (Egypt) in July 1991. He received his Master’s Degree in Civil Engineering from the Wayne State University in Michigan (USA) in August 1995. In September 2001, he received his Doctoral Degree in Environmental Engineering from the University of Alberta. Dr. Gamal El-Din joined the Environmental Engineering and Science Program at the University of Alberta in July 2001.