Removal of acid-extractable organics from oil sands process-affected water using carbon-based adsorbents

In surface mining process, 1.9 volumes of freshwater are used for each volume of bitumen produced and the used water, called oil sands process-affected water (OSPW), is stored in tailings ponds. Acid-extractable organics (AEO), one of the components of OSPW, are believed to be the main component of toxicity in OSPW, and create harmful effects to aquatic organisms, mammals and birds. To discharge OSPW into environment safely and reclaim the tailings ponds into natural ecosystem, the objective is to remove 90-99% AEO from OSPW. Canada has abundant resources of biomass waste materials to prepare biochar and activated carbon (AC), which can be applied for the removal of AEO from OSPW. In this thesis, the impact of biochar and AC properties, and synthesis methods for the removal of AEO from OSPW have been studied. Aspen wood AC samples were prepared by chemical (H3PO4) and physical (CO2) activation methods, and characterized and tested for the removal of AEO from steam-assisted gravity drainage (SAGD) water and OSPW. The role of physical properties of AC for AEO removal was investigated. The surface area and total pore volume of AC were positively correlated with AEO removal of SAGD water and OSPW.The impact of biochar properties on AEO adsorption from OSPW was studied. Biochar from wheat straw with the highest ash content (14 %) had the highest adsorption capacity (0.59 mg/g). The adsorption capacity had a positive correlation with metal content (mainly Al and Fe) of biochar. These results indicated that the metal sites acted as Lewis acids that can form coordination bonds with the naphthenates, the main constituent of the AEO. The influence of physical properties of carbon-based adsorbents on AEO adsorption kinetics was also investigated. As expected, there were diffusion limitations when adsorbing AEO onto microporous adsorbents, while larger pore materials were free of intra-particle diffusion limitations, as confirmed by the adsorption of alkylated cyclopentane carboxylic acid. The outcome of this research provides an insight into the application of biomass based adsorbents for AEO adsorption.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Chemical and Petroleum Engineering

Grantor dc:publisher.institution

Graduate Studies

Year dc:date.issued

2017

Author dc:creator

• Bhuiyan, Tazul

Advisor dc:contributor.advisor

• Hill, Josephine

Committee members dc:contributor.committeemember

• Abedi, Jalal
• Song, Hua
• Achari, Gopal
• Liu, Yang

• Engineering--Chemical

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

eng

DOI

http://dx.doi.org/10.11575/PRISM/27625

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:11023/4190