Degradation of ciprofloxacin in water by advanced oxidation process: kinetics study, influencing parameters and degradation pathways. Issue 5 (3rd March 2016)

• Record Type: Journal Article
• Authors: Sayed, Murtaza; Ismail, M.; Khan, Sanaullah; Tabassum, Safia; Khan, Hasan M.
• Is Part Of: Environmental technology. Volume 37:Issue 5(2016)
• Page Start: 590
• Page End: 602
• Publication Date: 2016-03-03
• Subjects: Advanced oxidation process -- ciprofloxacin -- degradation pathways -- radical scavenger -- water contaminants; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2015.1075597
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Gamma-radiation-induced degradation of ciprofloxacin (CIP) in aqueous solution and the factors affecting the degradation process have been investigated. The results showed that CIP (4.6 mg/L) was almost completely degraded at an absorbed dose of 870 Gy. The kinetic studies of aqueous solutions containing 4.6, 10, 15 and 17.9 mg/L indicated that the decomposition of CIP by gamma irradiation followed pseudo-first-order kinetics and the decay constant ( k ) decreased from 5.9 × 10 −3 to 1.6 × 10 −3 Gy −1 with an increase in CIP initial concentration from 4.6 to 17.9 mg/L. The effect of saturation of CIP solution with N2, N2 O or air on radiation-induced degradation of CIP was also investigated. The effects of radical scavengers, such as t -BuOH and i -PrOH, showed the role of reactive radicals towards degradation of CIP in the order of . The apparent second-order rate constant of with CIP was calculated to be 2.64 × 10 9 M −1 s −1 . The effects of solution pH as well as natural water contaminants, such as, , and, on CIP degradation by gamma-irradiation were also investigated. Major degradation products, including organic acids, were identified using UPLC-MS/MS and IC, and degradation pathways have been proposed.