title: Size characterization of incinerator fly ash using sedimentation/steric field-flow fractionation.
abstract: Fly ash particles emitted from municipal solid waste-incinerators are of environmental concern. This study aims to investigate the applicability of sedimentation/steric field-flow fractionation (Sd/StFFF) and to develop a Sd/StFFF method for the separation and size characterization of incinerator fly ash. This study focuses on the fly ash particles larger than approxiamtely 1 microm, which comprise more than 90% (w/w) of the fly ash. Fly ash is a complex mixture of particles having various chemical compositions, sizes, shapes, and densities. Prior to Sd/StFFF analysis, fly ash particles are prefractionated into six density classes using a modified centrifugal procedure. It was found that fly ash particles are most abundant in the density range between 2.4 and 2.8 g/cm3. Different density fractions seem to contain particles of different chemical compositions. The Sd/StFFF conditions for the size-characterization of fly ash are sample concentration, approximately 0.3% (w/v); dispersing medium, 50% ethanol in water; and carrier liquid, water with 1.0% FL-70 (ionic strength approximately 0.012 M). Sd/StFFF data show no significant differences in size distribution among different density fractions. Generally, the sizes obtained from Sd/StFFF are larger than those obtained from a Coulter Multisizer and microscopy, probably because of the irregular shapes of the fly ash particles.
authors.affiliation: Department of Chemistry, Yonsei University, Seoul, Korea.
authors.forename: Won-Suk
authors.initials: WS
authors.lastname: Kimt
authors.forename: Dai Woon
authors.initials: DW
authors.lastname: Lee
authors.forename: Seungho
authors.initials: S
authors.lastname: Lee
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D000465:Algorithms; D002244:Carbon / Q000032:analysis*; D002498:Centrifugation; D060729:Coal Ash; D007220:Industrial Waste / Q000032:analysis*; D008854:Microscopy, Electron; D010316:Particle Size; D052638:Particulate Matter
chemical_list: D000395:Air Pollutants, Occupational; D060729:Coal Ash; D007220:Industrial Waste; D052638:Particulate Matter; D002244:Carbon