1. Kinetics of Ultrasound-Enhanced Oxidation of p-Nitrophenol by Fenton's Reagent.
- Author
-
Zhao, Deming, Ding, Cheng, Wu, Chunxin, and Xu, Xinhua
- Subjects
CHEMICAL kinetics ,FENTON'S reagent ,AQUEOUS solutions ,NITROPHENOLS ,ULTRASONICS ,HYDROGEN-ion concentration ,OXIDATION ,TEMPERATURE effect - Abstract
Abstract: Aqueous solutions of p-Nitrophenol (PNP) were oxidized by Fenton''s reagent assisted by ultrasound (US) irradiation. The effects of operating parameters such as initial medium pH, initial concentration of PNP, the molar ratio of Fe
2+ /H2 O2 , the temperature and the type of saturating gas on the degradation rates of PNP were investigated. The results showed that both pH value and PNP concentration altered noticeably the reaction rates, with preferred operation conditions at low pH, and low PNP concentration. Among the four different saturating gases (namely Ar, O2 , air and N2 ), PNP degradation in an oxygen-saturated solution was the fastest. The addition of Fenton''s reagent could increase the PNP removal rate. PNP degradation followed apparent pseudo-first-order kinetics under US irradiation, Fenton''s reagent oxidation and the combined US/Fenton''s reagent oxidation process. The overall reaction rates were significantly enhanced in the US/Fenton''s reagent oxidation system, most likely because ultrasound could accelerate Fenton''s reagent to generate hydroxyl radical (. OH) and other reactive oxygen intermediates. There was an obvious synergetic effect in the combined US-Fenton''s reagent process. The observed synergetic effects of the US/Fenton''s reagent system resulted in an increase in the net PNP degradation rate by a factor of 2.06. [Copyright &y& Elsevier]- Published
- 2012
- Full Text
- View/download PDF