Degradation of naphthalenesulfonic acids by oxidation with ozone in aqueous phase

摘要: Sulfonic aromatic compounds are widely used in the textile industry for synthesis of azo dyes. The presence sulfonic group endows these with high water-solubility and resistance to biological treatment. present work analysed efficacy oxidation ozone treatment waters containing naphthalene-1-sulfonic acid, naphthalene-1,5-disulfonic acid naphthalene-1,3,6-trisulfonic acid. reactivity significantly decreased an increase number groups ring, showed lowest reaction rate. stoichiometry direct ozonization was around one mole per all cases. activation energy value very similar studied cases (37–42 kJ mol−1). contribution global at pH 2 observed decrease more sulfonic from a 69% 20% radical rate constant found be order 109×M−1 s−1 cases, although it slight reduction as ring increased. A follow-up study products each revealed highly oxidized organic acids sulfate ions. theoretical electronic density bond critical point that double bonds highest electron three positions 1–2, 3–4, 5–6 7–8. These initially attacked by via 1,3-dipolar cycloaddition.