Removal kinetics for gaseous NO and SO₂ by an aqueous NaClO₂ solution mist in a wet electrostatic precipitator

Removal kinetics for NO and SO₂ by NaClO₂ solution mist were investigated in a wet electrostatic precipitator. By varying the molar concentrations of NO, SO₂, and NaClO₂, the removal rates of NO and SO₂ confirmed to range from 34.8 to 72.9 mmol/m³ s and 36.6 to 84.7 mmol/m³ s, respectively, at a fixed gas residence time of 0.25 s. The rate coefficients of NO and SO₂ were calculated to be 0.679 (mmol/m³)^-0.33 s^-1 and 1.401 (mmol/m³)^-0.1 s^-1 based on the rates of the individual removal of NO and SO₂. Simultaneous removal of NO and SO₂ investigated after the evaluation of removal rates for their individual treatment was performed. At a short gas residence time, SO₂ gas removed more quickly by a mist of NaClO₂ solution than NO gas in simultaneous removal experiments. This is because SO₂ gas, which has a relatively high solubility in solution, was absorbed more rapidly at the gas-liquid interface than NO gas. NO and SO₂ gases were absorbed as nitrite [Formula: see text] and sulfite [Formula: see text] ions, respectively, by the NaClO₂ solution mist at the gas-liquid interface. Then, [Formula: see text] and [Formula: see text] were oxidized to nitrate [Formula: see text] and sulfate [Formula: see text], respectively, by reactions with [Formula: see text], ClO₂, HClO, and ClO in the liquid phase.