The ozonization of sodium lignosulfonate in the presence of hydrogen peroxide

The kinetics of ozonization of sodium lignosulfate (LS) in the presence of H₂O₂ was studied. The effective rate constants for the oxidation of LS and the total ozone consumption were determined. The k _eff = 30 ± 8 M^?1 s^?1 value was found to be independent of the concentration of H₂O₂. The total ozone consumption decreased as the concentration of H₂O₂ increased from 1.0 × 10^?4 to 1.0 × 10^?3 M because of the participation of the radicals generated in the O₃ + H₂O₂ reaction in LS transformations. The kinetic and UV and IR spectroscopy data allowed the conclusion to be drawn that the destruction of the LS aromatic system in the LS + O₃ + H₂O₂ reaction was caused by the interaction of LS with O₃, whereas radicals generated in this system contributed to deeper destruction of LS in the interaction of aliphatic LS macromolecule fragments with low-molecular-weight polymer oxidation products. The depth of polymer oxidation could be changed by varying the content of hydrogen peroxide in the system for LS ozonization.