title: Quantification of activated carbon contents in soils and sediments using chemothermal and wet oxidation methods.
abstract: Activated carbon (AC) strongly sorbs organic pollutants and can be used for remediation of soils and sediments. A method for AC quantification is essential to monitor AC (re)distribution. Since AC is black carbon (BC), two methods for BC quantification were tested for AC mixed in different soils and sediments: i) chemothermal oxidation (CTO) at a range of temperatures and ii) wet-chemical oxidation with a potassium dichromate/sulfuric acid solution. For three soils, the amount of AC was accurately determined by CTO at 375 degrees C. For two sediments, however, much of the AC disappeared during combustion at 375 degrees C, which could probably be explained by catalytic effects by sediment constituents. CTO at lower temperatures (325-350 degrees C) was a feasible alternative for one of the sediments. Wet oxidation effectively functioned for AC quantification in sediments, with almost complete AC recovery (81-92%) and low remaining amounts of native organic carbon (5-16%).
authors.affiliation: Department of Environmental Engineering, Norwegian Geotechnical Institute, PO Box 3930 Ullevål Stadion, N-0806 Oslo, Norway.
authors.forename: Rahel C
authors.initials: RC
authors.lastname: Brändli
authors.forename: Anders
authors.initials: A
authors.lastname: Bergsli
authors.forename: Upal
authors.initials: U
authors.lastname: Ghosh
authors.forename: Thomas
authors.initials: T
authors.lastname: Hartnik
authors.forename: Gijs D
authors.initials: GD
authors.lastname: Breedveld
authors.forename: Gerard
authors.initials: G
authors.lastname: Cornelissen
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000295:instrumentation*; D019015:Geologic Sediments / Q000737:chemistry*; D006358:Hot Temperature; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002606:Charcoal