title: Carbon speciation in ash, residual waste and contaminated soil by thermal and chemical analyses.
abstract: Carbon in waste can occur as inorganic (IC), organic (OC) and elemental carbon (EC) each having distinct chemical properties and possible environmental effects. In this study, carbon speciation was performed using thermogravimetric analysis (TGA), chemical degradation tests and the standard total organic carbon (TOC) measurement procedures in three types of waste materials (bottom ash, residual waste and contaminated soil). Over 50% of the total carbon (TC) in all studied materials (72% in ash and residual waste, and 59% in soil) was biologically non-reactive or EC as determined by thermogravimetric analyses. The speciation of TOC by chemical degradation also showed a presence of a non-degradable C fraction in all materials (60% of TOC in ash, 30% in residual waste and 13% in soil), though in smaller amounts than those determined by TGA. In principle, chemical degradation method can give an indication of the presence of potentially inert C in various waste materials, while TGA is a more precise technique for C speciation, given that waste-specific method adjustments are made. The standard TOC measurement yields exaggerated estimates of organic carbon and may therefore overestimate the potential environmental impacts (e.g. landfill gas generation) of waste materials in a landfill environment.
authors.affiliation: Division of Waste Science and Technology, Department of Civil, Mining and Environmental Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden. jurate.kumpiene@ltu.se
authors.forename: Jurate
authors.initials: J
authors.lastname: Kumpiene
authors.forename: Ryan
authors.initials: R
authors.lastname: Robinson
authors.forename: Evelina
authors.initials: E
authors.lastname: Brännvall
authors.forename: Désirée
authors.initials: D
authors.lastname: Nordmark
authors.forename: Henrik
authors.initials: H
authors.lastname: Bjurström
authors.forename: Lale
authors.initials: L
authors.lastname: Andreas
authors.forename: Anders
authors.initials: A
authors.lastname: Lagerkvist
authors.forename: Holger
authors.initials: H
authors.lastname: Ecke
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D013058:Mass Spectrometry; D012037:Refuse Disposal; D012987:Soil / Q000737:chemistry*; D013818:Thermogravimetry; D014866:Waste Products / Q000032:analysis*
chemical_list: D012987:Soil; D014866:Waste Products; D002244:Carbon