title: Selenium speciation in flue desulfurization residues.
abstract: Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk.
authors.affiliation: Institute for Combustion Science and Environmental Technology (ICSET), Western Kentucky University, 2413 Nashville Rd., Bowling Green, Kentucky 42101, USA. zlp1968@hotmail.com
authors.forename: Liping
authors.initials: L
authors.lastname: Zhong
authors.forename: Yan
authors.initials: Y
authors.lastname: Cao
authors.forename: Wenying
authors.initials: W
authors.lastname: Li
authors.forename: Kechang
authors.initials: K
authors.lastname: Xie
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Pan
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D005740:Gases / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry; D012643:Selenium / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014881:Water Supply / Q000032:analysis
chemical_list: D001894:Borohydrides; D005740:Gases; D017942:Nitric Acid; D013455:Sulfur; C025364:sodium borohydride; D012643:Selenium