title: Adsorption of acid-extractable organics from oil sands process-affected water onto biomass-based biochar: Metal content matters.
abstract: The impact of biochar properties on acid-extractable organics (AEO) adsorption from oil sands process-affected water (OSPW) was studied. Biochar from wheat straw with the highest ash content (14%) had the highest adsorption capacity (0.59 mg/g) followed by biochar from pulp mill sludge, switchgrass, mountain pine, hemp shives, and aspen wood. The adsorption capacity had no obvious trend with surface area, total pore volume, bulk polarity and aromaticity. The large impact of metal content was consistent with the carboxylates (i.e., naphthenate species) in the OSPW binding to the metals (mainly Al and Fe) on the carbon substrate. Although the capacity of biochar is still approximately two orders of magnitude lower than that of a commercial activated carbon, confirming the property (i.e., metal content) that most influenced AEO adsorption, may allow biochar to become competitive with activated carbon after normalizing for cost, especially if this cost includes environmental impacts.
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4, Canada.
authors.forename: Tazul I
authors.initials: TI
authors.lastname: Bhuiyan
authors.affiliation: Thermochemical Processing, InnoTech Alberta, P.O. Bag 4000, Vegreville, T9C 1T4, Alberta, Canada.
authors.forename: Jin K
authors.initials: JK
authors.lastname: Tak
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4, Canada.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sessarego
authors.affiliation: Thermochemical Processing, InnoTech Alberta, P.O. Bag 4000, Vegreville, T9C 1T4, Alberta, Canada.
authors.forename: Don
authors.initials: D
authors.lastname: Harfield
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4, Canada. Electronic address: jhill@ucalgary.ca.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Hill
mesh_terms: D000327:Adsorption; D018533:Biomass; D002188:Cannabis; D002264:Carboxylic Acids / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D007220:Industrial Waste; D008670:Metals / Q000737:chemistry*; D061329:Oil and Gas Fields; D008897:Panicum; D028223:Pinus; D032107:Populus; D014908:Triticum; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D007220:Industrial Waste; D008670:Metals; D014874:Water Pollutants, Chemical; C540010:biochar; D002606:Charcoal
keywords: Acid-extractable organics; Adsorption; Biochar; Naphthenic acids; Oil sands process-affected water