title: Dissolution behavior of selenium from coal fly ash particles for the development of an acid-washing process.
abstract: Coal fly ash emitted from coal-fired electric power stations generally contains environmentally regulated trace elements. In particular, boron, arsenic, and selenium have been recognized as troublesome trace elements because elutions from the fly ash contain them. In order to design an effective removal process for these trace elements, we have developed and investigated an acid-washing process. The dissolution behavior of selenium from coal fly ash particles was focused on for the improvement of the process, and was found to greatly depend on the pH of the acid solutions. The species of selenium in solutions with a pH of around 0-1 was determined to be H2SeO3. The dissolved H2SeO3 transformed into HSeO3- and adsorbed onto the surface of the ash particles in solution upon elevation of the pH. The re-elution of the absorbed HSeO3- as SeO3(2-) at a pH of 10 was also confirmed, and will cause the elution of the excess selenium from the acid-washed ash.
authors.affiliation: Institute for Materials Research, Graduate School of Environmental Studies, Tohoku University, Sendai 980-8577, Japan. shunsuke-k@imr.tohoku.ac.jp
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kashiwakura
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohno
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kubo
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Matsubae
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagasaka
mesh_terms: D000143:Acids / Q000737:chemistry*; D000327:Adsorption; D060729:Coal Ash / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006863:Hydrogen-Ion Concentration; D052638:Particulate Matter / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000143:Acids; D060729:Coal Ash; D052638:Particulate Matter; D012643:Selenium