title: Modified sequential extraction for biochar and petroleum coke: Metal release potential and its environmental implications.
abstract: A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual). Petroleum coke was the most stable material, with a similar metal distribution pattern as the sewage sludge biochar. The applied sequential extraction method represents a suitable technique to recover metals from these materials, and is a valuable tool in understanding the metal retaining and leaching capability of various biochar types and carbonaceous petroleum coke samples.
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton T6G 2E3, Canada. Electronic address: vongunte@ualberta.ca.
authors.forename: Konstantin
authors.initials: K
authors.lastname: von Gunten
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton T6G 2E3, Canada.
authors.forename: Md Samrat
authors.initials: MS
authors.lastname: Alam
authors.affiliation: Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton T6G 2R3, Canada.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Hubmann
authors.affiliation: Korea Biochar Research Center & School of Natural Resources and Environmental Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Ok
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton T6G 2E3, Canada.
authors.forename: Kurt O
authors.initials: KO
authors.lastname: Konhauser
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton T6G 2E3, Canada.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Alessi
mesh_terms: D003077:Coke; D019216:Metals, Heavy; D061329:Oil and Gas Fields; D010578:Petroleum; D012722:Sewage
chemical_list: D003077:Coke; D019216:Metals, Heavy; D010578:Petroleum; D012722:Sewage
keywords: Agriculture; Biochar digestion; Contaminants; Metal release; Sequential extraction