II(a). Oxidation-reduction reactions involving inorganic substrates. Aqueous chemistry of inorganic free radicals. Part 3.—The kinetics and mechanism of the reaction of peroxydisulphate ion and hydrogen peroxide

Abstract

A kinetic study has been made of the reaction of peroxydisulphate ion and hydrogen peroxide in aqueous solution at 30°C. In three different ranges of concentration of the reactants the rate law approaches three different limiting forms : (i) first order in peroxydisulphate and half order in hydrogen peroxide, (ii) first order in peroxydisulphate and (iii) half order in peroxydisulphate. The proposed mechanism involves a chain reaction, with the SO,-, OH, and H02 radicals carrying and terminating the reaction chain.The present paper is concerned with the kinetics of the reaction of persulphate ion and hydrogen peroxide, with the results yielding detailed information about the reaction mechanism and about various aspects of the chemistry of the H02, SO4 and OH radicals.When hydrogen peroxide, hereafter referred to as peroxide, reacts with persulphate ion under the conditions outlined below, the stoichiometry of the reaction does not deviate appreciably from that given by eqn. (I) : S 2 0 g -+ H202+ O2 +2HSOq.

Column experiment on activation aids and biosurfactant application to the persulphate treatment of chlorophene-contaminated soil

“…A multiradical attack mechanism was proposed to explain the enhanced contaminant destruction in the system, [48] and it was suggested that successive production of sulphate and hydroxyl radicals can take place. [49] In a combined formulation of persulphate with hydrogen peroxide, the latter can degrade the contaminant to more reactive by-products, whereas persulphate provides a longer lasting treatment for deeper and more recalcitrant contamination.…”

Kinetics and Mechanism of Oxidations by Peroxydisulfate.

“…Hydrogen peroxide and peroxydisulfate react together to form oxygen according to the equation (42,162) where equations (3), ( 5), and (6) are not simple steps.…”

Reaction performance study on denitration in aqueous solution of the dual oxidant (H2O2/S2)

“…Based on the previous studies , the removal of NO from flue gas by using the dual oxidant (H 2 O 2 /S 2 ) solution was very complicated. The , derived from the thermal decomposition of the persulfate, can stimulate the formation of HO• and hydroperoxyl radical (HO 2 •).…”

“…The dual oxidant composed of H 2 O 2 and Na 2 S 2 O 8 attracts the widely attention, because which has the advantages of the low cost of hydrogen peroxide and the strong oxidation ability of sodium persulfate, and will not cause secondary pollution to the environment. The existing studies have showed that the hydroxyl free radicals (HO•) and sulfate free radicals ( ) coexisted in the dual oxidant system have a synergistic effect on the oxidation of pollutants. At present, Zhao et al .…”

“…The dual oxidant composed of H 2 O 2 and Na 2 S 2 O 8 attracts the widely attention, because which has the advantages of the low cost of hydrogen peroxide and the strong oxidation ability of sodium persulfate, and will not cause secondary pollution to the environment. The existing studies [16][17][18][19] have showed that the hydroxyl free radicals (HO•) and sulfate free radicals (SO •2 4 ) coexisted in the dual oxidant system have a synergistic effect on the oxidation of pollutants. At present, Zhao et al [5] have studied the semidry integrative process for simultaneous removal of SO 2 and NO by utilizing a vaporized H 2 O 2 /Na 2 S 2 O 8 system, the results have showed that the simultaneous removal efficiencies of NO and SO 2 are 79.6% and 98.9% respectively at the temperature of 1108C, and the simultaneously desulfurization and denitration cost of this way is lower than that of WFGD-SCR.…”