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1673634 
Journal Article 
Kinetic study of ambient-temperature reduction of Fe(III)edta by Na2S2O4 
Suchecki, TT; Mathews, B; Kumazawa, H 
2005 
Yes 
Industrial and Engineering Chemistry Research
ISSN: 0888-5885
EISSN: 1520-5045 
44 
12 
4249-4253 
WOS:000229791000012 
The chelate method can provide simultaneous control of combustion flue gases SO2/NOx by scrubbing into aqueous solutions of ferrous chelates, e.g., Fe(II)edta, an ethylenediaminetetraacetic acid. Because of oxidation of Fe(II)edta to completely inactive in the system Fe(III)edta, the absorption solution requires regeneration. A new proposal here for this process is based on the direct reduction of Fe(III)edta by a dithionite ion, S2O42-. The rate equation for the reduction of Fe(III)edta by dithionite was derived in terms of the rate-determining-step approximation method. A kinetic study of this process was conducted by using a bubbling-type batch reactor. The following initial parameters were examined: Fe(III)edta and Na2S2O4 concentrations, pH, and oxygen concentration. It was concluded that dithionite is a promising reducing agent for the regeneration of the absorption solution of the chelate method. The ambient-temperature regeneration process should be operated under the following conditions: pH(0) = 3.5-9.0 and [Na2S2O4](0)/[Fe(III)edta](0) = 0.6.