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Reduction of ferrate(VI) and oxidation of cyanate in a Fe(VI)-TiO2-UV-NCO- system.
Chemosphere. 2008 Aug; 72(11):1694-9.C

Abstract

The aqueous photocatalytic degradation of cyanate (NCO(-)), which is a long-lived neurotoxin formed during the remediation of cyanide in industrial waste streams, was studied in the ferrate(VI)-UV-TiO2-NCO(-) system. Kinetics measurements of the photocatalytic reduction of ferrate(VI) were carried out as a function of [NCO(-)], [ferrate(VI)], [O(2)], light intensity (I(o)), and amount of TiO2 in suspensions at pH 9.0. The photocatalytic reduction rate of ferrate(VI) in the studied system can be expressed as -d[Fe(VI)]/dt=kI(o)(0.5) [NCO(-)] [TiO2]. The rate of photocatalytic oxidation of cyanate with ferrate(VI) was greater than the rate in the analogous system without ferrate(VI). The possibility of involvement of reactive ferrate(V) species for this enhancement was determined by studying the reactivity of ferrate(V) with NCO(-) in a homogeneous solution using a premix pulse radiolysis technique. The rate constant for the reaction of ferrate(V) and NCO(-) in alkaline medium was estimated to be (9.60+/-0.07) x 10(2) M(-1) s(-1), which is much slower than the ferrate(VI) self-decomposition reaction (k approximately 10(7) M(-1) s(-1)). An analysis of the kinetic data in the Fe(VI)-UV-TiO2-NCO(-) system suggests that ferrate(V) is not directly participating in the oxidation of cyanate. Possible reactions in the system are presented to explain results of ferrate(VI) reduction and oxidation of cyanate.

Authors+Show Affiliations

Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901, United States.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

18561980

Citation

Winkelmann, Kurt, et al. "Reduction of ferrate(VI) and Oxidation of Cyanate in a Fe(VI)-TiO2-UV-NCO- System." Chemosphere, vol. 72, no. 11, 2008, pp. 1694-9.
Winkelmann K, Sharma VK, Lin Y, et al. Reduction of ferrate(VI) and oxidation of cyanate in a Fe(VI)-TiO2-UV-NCO- system. Chemosphere. 2008;72(11):1694-9.
Winkelmann, K., Sharma, V. K., Lin, Y., Shreve, K. A., Winkelmann, C., Hoisington, L. J., & Yngard, R. A. (2008). Reduction of ferrate(VI) and oxidation of cyanate in a Fe(VI)-TiO2-UV-NCO- system. Chemosphere, 72(11), 1694-9. https://doi.org/10.1016/j.chemosphere.2008.05.008
Winkelmann K, et al. Reduction of ferrate(VI) and Oxidation of Cyanate in a Fe(VI)-TiO2-UV-NCO- System. Chemosphere. 2008;72(11):1694-9. PubMed PMID: 18561980.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Reduction of ferrate(VI) and oxidation of cyanate in a Fe(VI)-TiO2-UV-NCO- system. AU - Winkelmann,Kurt, AU - Sharma,Virender K, AU - Lin,Yekaterina, AU - Shreve,Katherine A, AU - Winkelmann,Catherine, AU - Hoisington,Laura J, AU - Yngard,Ria A, Y1 - 2008/06/17/ PY - 2008/02/18/received PY - 2008/04/29/revised PY - 2008/05/05/accepted PY - 2008/6/20/pubmed PY - 2008/10/22/medline PY - 2008/6/20/entrez SP - 1694 EP - 9 JF - Chemosphere JO - Chemosphere VL - 72 IS - 11 N2 - The aqueous photocatalytic degradation of cyanate (NCO(-)), which is a long-lived neurotoxin formed during the remediation of cyanide in industrial waste streams, was studied in the ferrate(VI)-UV-TiO2-NCO(-) system. Kinetics measurements of the photocatalytic reduction of ferrate(VI) were carried out as a function of [NCO(-)], [ferrate(VI)], [O(2)], light intensity (I(o)), and amount of TiO2 in suspensions at pH 9.0. The photocatalytic reduction rate of ferrate(VI) in the studied system can be expressed as -d[Fe(VI)]/dt=kI(o)(0.5) [NCO(-)] [TiO2]. The rate of photocatalytic oxidation of cyanate with ferrate(VI) was greater than the rate in the analogous system without ferrate(VI). The possibility of involvement of reactive ferrate(V) species for this enhancement was determined by studying the reactivity of ferrate(V) with NCO(-) in a homogeneous solution using a premix pulse radiolysis technique. The rate constant for the reaction of ferrate(V) and NCO(-) in alkaline medium was estimated to be (9.60+/-0.07) x 10(2) M(-1) s(-1), which is much slower than the ferrate(VI) self-decomposition reaction (k approximately 10(7) M(-1) s(-1)). An analysis of the kinetic data in the Fe(VI)-UV-TiO2-NCO(-) system suggests that ferrate(V) is not directly participating in the oxidation of cyanate. Possible reactions in the system are presented to explain results of ferrate(VI) reduction and oxidation of cyanate. SN - 0045-6535 UR - https://www.unboundmedicine.com/medline/citation/18561980/Reduction_of_ferrate_VI__and_oxidation_of_cyanate_in_a_Fe_VI__TiO2_UV_NCO__system_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0045-6535(08)00627-9 DB - PRIME DP - Unbound Medicine ER -