title: Study of photodegradation and photooxidation of p-arsanilic acid in water solutions at pH = 7: kinetics and by-products.
abstract: The paper presents the kinetics and proposed pathways photodegradation and photooxidation of p-arsanilic acid, in a neutral environment by ozone and hydrogen peroxide. The results showed that in a neutral environment, photoozonation process was characterized by the highest decomposition rate constant (k) (k = 31.8 × 10(-3) min(-1)). The rate constants decreased in the order UV/O3 > O3 > UV/H2O2 > H2O2 > UV. It was also found that under pH = 7, decomposition of p-arsanilic acid leads mainly to the formation of aniline, which undergoes secondary reactions. Intermediate products of oxidation and photooxidation by hydrogen peroxide like nitrobenzene, nitrophenol, azobenzenes, and phenylazophenol were identified depending on processes. However, in the photodegradation process, formation of nitrasone as a reaction product of p-arsanilic acid with oxygen in the singlet state was observed. In the case of ozonation and photoozonation, in addition, aniline formation of carboxylic acids was observed.
authors.affiliation: Institute of Non-Ferrous Metals, Gliwice, Sowinskiego 5, Poland. mariannac@imn.gliwice.pl.
authors.forename: Marianna
authors.initials: M
authors.lastname: Czaplicka
authors.affiliation: Institute of Non-Ferrous Metals, Gliwice, Sowinskiego 5, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Jaworek
authors.affiliation: Institute of Non-Ferrous Metals, Gliwice, Sowinskiego 5, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Bąk
mesh_terms: D001147:Arsanilic Acid / Q000737:chemistry* / Q000528:radiation effects*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry; D010782:Photolysis; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D010126:Ozone; D006861:Hydrogen Peroxide; D001147:Arsanilic Acid
keywords: Advanced oxidation; By-products; Kinetics; Photodegradation; p-Arsanilic acid