Removal of Naphthenic Acids from Oil Sands Process-Affected Water (ospw) Using Mixtures of Designer Biochar and Petroleum Coke
Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
The oil sands industries in Alberta produce large volumes of oil sands process-affected water (OSPW) as a result of bitumen extraction and upgrading processes. Naphthenic acids (NAs) are constituents of OSPW, and are acutely toxic to aquatic life. The recycling and /or safe return of OSPW into the environment is major challenge for the oil sands industry; therefore, proper OSPW treatment technologies/options are needed. Oil sands petroleum coke is a byproduct of the processing of oil sands, and is abundantly available at mining sites. Biochars are the byproducts of the carbonization and/or pyrolysis of many types of biomass. Both of them are proven in the removal of a wide range organics from water, including chlorinated ethenes, PAHs, and other hydrophobic organic contaminants. A number of studies have characterized naphthenic acids adsorption behavior and removal from OSPW under specific process conditions. In this study, series of adsorption experiments of selected model of NAs onto cokes, biochars, and coke-biochar mixtures will be conducted as a function of pH and sorbent-to-NA ratios. We will use a surface complexation approach to derive adsorption constants and model molecular scale adsorption reactions. Using these models, predictions of NAs removal from OSPW will be adjustable for treatment-specific conditions. The outcome of this study will not only be of scientific interest, but will provide a tool to industry that can be used in on-site OSPW treatment planning.
AAPG Search and Discovery Article #90199 © 2014 AAPG Foundation 2014 Grants-in-Aid Projects