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Ferrates(FeVI, FeV, and FeIV) oxidation of iodide: Formation of triiodide.
Chemosphere. 2016 Feb; 144:1156-61.C

Abstract

The presence of iodide (I(-)) in water during disinfection and oxidative treatment of water is a potential health concern because of the formation of iodinated disinfection by-products (DBPs), which may be more toxic than chlorinated DBPs. The kinetics of the oxidation of I(-) by a greener oxidant, ferrate(VI) (Fe(VI)O4(2-), Fe(VI)) was determined as a function of pH. The second-order rate constants (k, M(-1) s(-1)) decreased from 3.9 × 10(4) M(-1) s(-1) at pH 5.0 to 1.2 × 10(1) M(-1) s(-1) at pH 10.3. The kinetics results could be described by the reactivity of monoprotonated species of Fe(VI) (HFe(VI)O4(-)) with I(-). In excess I(-) concentration, triiodide (I3(-)) was formed and the stoichiometry of ∼1:1 ([Fe(VI)]:[I3(-)]) was found in both acidic and basic pH. Ferrate(V) (Fe(V)O4(3-), Fe(V)) and ferrate(IV) (Fe(VI)O4(4-), Fe(IV)) also showed the formation of I3(-) in presence of excess I(-). A mechanism of the formation of I3(-) is proposed, which is consistent with the observed stoichiometry of 1:1. The oxidative treatment of I(-) in water will be rapid (t1/2 = 0.6 s at pH 7.0 using 10 mg L(-1) K2FeO4). The implications of the results and their comparison with the oxidation of I(-) by conventional disinfectants/oxidants in water treatment are briefly discussed.

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Publisher Full Text (DOI)

Authors+Show Affiliations

Kralchevska RP
Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and Experimental Physics, Faculty of Science, Palacký University, Olomouc, Czech Republic.
Sharma VK
Department of Occupational and Environmental Health, School of Public Health, Texas A&M University, College Station, TX 77843, USA. Electronic address: vsharma@sph.tamhsc.edu.
Machala L
Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and Experimental Physics, Faculty of Science, Palacký University, Olomouc, Czech Republic.
Zboril R
Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and Experimental Physics, Faculty of Science, Palacký University, Olomouc, Czech Republic.

MeSH

DisinfectantsHalogenationIodidesIronKineticsOxidantsOxidation-ReductionWater Pollutants, ChemicalWater Purification

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

26461440

Citation

Kralchevska, Radina P., et al. "Ferrates(FeVI, FeV, and FeIV) Oxidation of Iodide: Formation of Triiodide." Chemosphere, vol. 144, 2016, pp. 1156-61.
Kralchevska RP, Sharma VK, Machala L, et al. Ferrates(FeVI, FeV, and FeIV) oxidation of iodide: Formation of triiodide. Chemosphere. 2016;144:1156-61.
Kralchevska, R. P., Sharma, V. K., Machala, L., & Zboril, R. (2016). Ferrates(FeVI, FeV, and FeIV) oxidation of iodide: Formation of triiodide. Chemosphere, 144, 1156-61. https://doi.org/10.1016/j.chemosphere.2015.09.091
Kralchevska RP, et al. Ferrates(FeVI, FeV, and FeIV) Oxidation of Iodide: Formation of Triiodide. Chemosphere. 2016;144:1156-61. PubMed PMID: 26461440.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ferrates(FeVI, FeV, and FeIV) oxidation of iodide: Formation of triiodide. AU - Kralchevska,Radina P, AU - Sharma,Virender K, AU - Machala,Libor, AU - Zboril,Radek, Y1 - 2015/10/23/ PY - 2015/06/30/received PY - 2015/09/01/revised PY - 2015/09/24/accepted PY - 2015/10/14/entrez PY - 2015/10/16/pubmed PY - 2016/8/10/medline KW - Disinfection by-products KW - Ferrate KW - Iodide KW - Mechanism KW - Oxidation SP - 1156 EP - 61 JF - Chemosphere JO - Chemosphere VL - 144 N2 - The presence of iodide (I(-)) in water during disinfection and oxidative treatment of water is a potential health concern because of the formation of iodinated disinfection by-products (DBPs), which may be more toxic than chlorinated DBPs. The kinetics of the oxidation of I(-) by a greener oxidant, ferrate(VI) (Fe(VI)O4(2-), Fe(VI)) was determined as a function of pH. The second-order rate constants (k, M(-1) s(-1)) decreased from 3.9 × 10(4) M(-1) s(-1) at pH 5.0 to 1.2 × 10(1) M(-1) s(-1) at pH 10.3. The kinetics results could be described by the reactivity of monoprotonated species of Fe(VI) (HFe(VI)O4(-)) with I(-). In excess I(-) concentration, triiodide (I3(-)) was formed and the stoichiometry of ∼1:1 ([Fe(VI)]:[I3(-)]) was found in both acidic and basic pH. Ferrate(V) (Fe(V)O4(3-), Fe(V)) and ferrate(IV) (Fe(VI)O4(4-), Fe(IV)) also showed the formation of I3(-) in presence of excess I(-). A mechanism of the formation of I3(-) is proposed, which is consistent with the observed stoichiometry of 1:1. The oxidative treatment of I(-) in water will be rapid (t1/2 = 0.6 s at pH 7.0 using 10 mg L(-1) K2FeO4). The implications of the results and their comparison with the oxidation of I(-) by conventional disinfectants/oxidants in water treatment are briefly discussed. SN - 1879-1298 UR - https://www.unboundmedicine.com/medline/citation/26461440/Ferrates_FeVI_FeV_and_FeIV__oxidation_of_iodide:_Formation_of_triiodide_ DB - PRIME DP - Unbound Medicine ER -