Ozonation of 1-naphthalene, 1,5-naphthalene, and 3-nitrobenzene sulphonic acids in aqueous solutions.
Ozone oxidation kinetics of 1-naphthalene (INS), 1,5-naphthalene (1,5NDS), and 3-nitrobenzene (3NBS) sulphonic acid is reported here. The contribution of indirect free-radical pathways and direct ozone reactions are accounted for in the proposed model. Second order kinetic constants of direct reactions were estimated at around 252 (M(-1)s(-1)), 41 (M(-1)s(-1)) and 22 (M(-1)s(-1)), for INS, 1,5NDS, and 3NBS sulphonic adds, respectively. At pH 3, the indirect reaction accounted for 2%, 15% and 4% of total primary oxidation of 1NS, 1,5NBS, and 3NBS sulphonic acids, respectively. At pH 9, indirect reaction contribution increased to 73%, 84% and 48%, respectively. C4 compounds (maleic and fumaric acids), C2 (oxalic), C1 (formic) and sulphate were identified as oxidation by-products in all cases. TOC slowly decreased throughout ozonation, reaching around 40-60% and 60-70% reduction over 90 min, at pH 7 and 3, respectively.
Calderara
V
V
Chemical Engineering Dept, University of Concepción, Chile.
Jekel
M
M
Zaror
C
C
D007700:Kinetics; D009281:Naphthalenes / Q000737:chemistry*; D009578:Nitrobenzenes / Q000737:chemistry*; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D009281:Naphthalenes; D009578:Nitrobenzenes; D010083:Oxidants, Photochemical; D013451:Sulfonic Acids; D010126:Ozone