title: Oxidative degradation of 1,5-naphthalenedisulfonic acid in aqueous solutions by microwave irradiation in the presence of H2O2.
abstract: Sulfonated aromatic pollutants such as Armstrong's acid, or 1,5-naphthalenedisulfonic acid (NDS), are recalcitrant to environmental breakdown and microbial treatment. This study investigated the effects of H(2)O(2) concentration, pH, microwave (MW) power and irradiation time on the oxidative degradation of NDS in aqueous solutions. The formation of hydroxyl radicals as the active oxidant was confirmed by electron paramagnetic resonance spin trapping. A combination of both H(2)O(2) and MW heating proved essential for NDS degradation. Degradation factors of f70% were obtained after about 20min of irradiation at [H(2)O(2)]:[NDS] ratios=10. Acidic conditions were found to be more favorable to the degradation of NDS, and the process follows pseudo-first-order kinetics. Attempts to scale-up the process using a conventional MW reactor provided less striking results.
authors.affiliation: Dipartimento di Scienze dell'Ambiente e della Vita, Università del Piemonte Orientale Amedeo Avogadro, Alessandria, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Ravera
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buico
authors.forename: Fabio
authors.initials: F
authors.lastname: Gosetti
authors.forename: Claudio
authors.initials: C
authors.lastname: Cassino
authors.forename: Davide
authors.initials: D
authors.lastname: Musso
authors.forename: Domenico
authors.initials: D
authors.lastname: Osella
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004785:Environmental Pollutants / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008872:Microwaves; D009281:Naphthalenes / Q000737:chemistry*; D010084:Oxidation-Reduction; D013457:Sulfur Compounds / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D009281:Naphthalenes; D013457:Sulfur Compounds; D014867:Water; D006861:Hydrogen Peroxide