Denitrification utilizing a vaporized enhanced-Fenton reagent: kinetics and feasibility

Abstract

This paper proposes a novel integrative process for NO removal, in which NO was initially oxidized by a vaporized enhanced-Fenton reagent (EF), composed of hydrogen peroxide, ferrous and peroxyacetic acid (PAA), then absorbed by Ca(OH)₂. The effects of EF constitution, the reaction temperature, the pH of EF solution and the SO₂ concentration on NO removal were systematically investigated, and the experimental results indicated that both FeSO₄ and PAA can significantly promote the oxidation rate of NO; the decreasing of pH and increasing of temperature played a key role in enhancing NO removal. The NO depletion exhibited a pseudo-first order kinetics pattern in 1–2 half-lives, based on the macrokinetics of NO oxidation. In addition, the rate constants determined in the temperature range of 60 to 120 °C were well fitted to the Arrhenius equation, yielding the apparent activation energy of 14.1 kJ mol⁻¹. The mechanism of NO oxidation was also speculated.