Record Display for the EPA National Library Catalog


Main Title Validation of the Hoffmann and Edwards' S(IV)-H2O2 Mechanism.
Author Overton, J. H. ;
CORP Author Northrop Services, Inc., Research Triangle Park, NC.;Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1985
Report Number EPA-68-02-4033; EPA/600/J-85/089;
Stock Number PB85-239192
Additional Subjects Air pollution ; Oxidation ; Sulfur ; Hydrogen peroxide ; Reaction kinetics ; pH ; Least squares method ; Experimental design ; Graphs(Charts) ; Reprints ; Acid rain ; Chemical reaction mechanisms ; Hoffmann Edward's mechanism
Library Call Number Additional Info Location Last
NTIS  PB85-239192 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 5p
As a result of the acid rain problem two papers have been published which report the oxidation rate of dissolved S(IV) by H2O2. The data and that of the earlier works of Hoffmann and Edwards (1975) and others represents a data base of rates that were determined in conditions of different pH's (0 to greater than 12), temperatures (7 C - 41 C) and buffer systems. Hoffmann and Edwards postulated a mechanism to explain the reaction for pH about 8. The findings of others are consistent with the mechanism in the same range. However, the data of Hoffmann and Edwards and others in the intermediate pH range exhibit the same 0.7 order relationship with (H(+1)) that was pointed out by Dasgupta (1980). The purpose of the note is to show that the rates in the intermediate pH range are consistent with the mechanism and with the postulated (Hoffmann and Edwards) first-order dependence on (H(+1)). This is demonstrated by taking into account the effects of temperature, pH, buffer system and using the method of regression for curve fitting.