Radiolysis of 1-naphthol in aqueous solutions

• Published in: Journal of radioanalytical and nuclear chemistry Vol. 286; no. 1; pp. 287 - 293
• Main Authors: Ngo, Thang M., Hoang, Nam M., Tran, Tram T. M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2010
• Subjects: Aqueous solutions; Chemistry; Chemistry and Materials Science; Constants; Degradation; Diagnostic Radiology; Empirical analysis; Hadrons; Heavy Ions; Hydrochloric acid; Inorganic Chemistry; Kinetic equations; Nuclear Chemistry; Nuclear Physics; Physical Chemistry; Radiolysis; 1-Naphthol; Water treatment; Gamma-radiolysis
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-010-0652-z

The effects of absorbed doses, initial pH and 1-naphthol concentration onto its radiolysis in aqueous sulphuric and hydrochloric acids by gamma rays from 60 Co were investigated. Under the experimental conditions, 1-naphthol degradation yields increased with increasing the absorbed doses (0.3–3.0 kGy) and with decreasing the initial 1-naphthol concentration (20–1 ppm). It was found out that the hydrated electrons did not play any significant roles in 1-naphthol radiolysis, as the degradation yields were higher at pH 0  ~ 0.46 compared to those at pH 0  ~ 2.0–5.0. The corresponding radiolytic yields G(−1-naphthol) were (6.13 ± 1.00)) × 10 −2 and (5.11 ± 0.22) × 10 −2  μmol/J in sulphuric acids, (15.61 ± 3.85) × 10 −2 and (4.76 ± 0.48) × 10 −2  μmol/J in hydrochloric acids. 1-Naphthol degradation rates could be described by the kinetic equations of pseudo-first-order reactions. An empirical relation between the observed reaction constants k D and the initial 1-naphthol concentrations was established, enabling to predict the absorbed doses required for a given treatment efficiency. Three products of 1-naphthol degradation were revealed using an HPLC/UV procedure.