title: Elucidation of the mechanism of reaction between S2O8(2-), Selenite and Mn2+ in aqueous solution and limestone-gypsum FGD liquor.
abstract: The mechanism of reaction between peroxodisulfate ion (S2O8(2-)), selenite (Se(IV)O3(2-)) and Mn(2+) as an inhibitor of selenite oxidation was studied using aqueous solutions composed of commercial reagents, as well as limestone-gypsum flue gas desulfurization (FGD) liquors sampled from coal fired power plants. The oxidation of selenite to selenate (Se(VI)O4(2-)) is promoted by the sulfate ion radical (SO4(-)) which results from decomposition of S2O8(2-). In the presence of Mn(2+), selenite oxidation was prevented due to the difference in rates of reaction with SO4(-). The ratio of the oxidation rate constants of selenite and Mn(2+) with SO4(-) was determined over a temperature range of 40-60 °C, and was found to be little influenced by the various coexisting components in FGD liquors.
authors.affiliation: Energy Engineering Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI) , 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Akiho
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ito
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Matsuda
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yoshioka
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D007220:Industrial Waste; D008345:Manganese / Q000737:chemistry*; D010084:Oxidation-Reduction; D017680:Potassium Compounds / Q000737:chemistry*; D011210:Power Plants; D020887:Selenious Acid / Q000737:chemistry*; D012996:Solutions; D013431:Sulfates / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D017680:Potassium Compounds; D012996:Solutions; D013431:Sulfates; D008345:Manganese; C009007:potassium persulfate; D020887:Selenious Acid; D002119:Calcium Carbonate; D002133:Calcium Sulfate