期刊
JOURNAL OF WATER PROCESS ENGINEERING
卷 37, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.jwpe.2020.101535
关键词
Advanced oxidative process; Indigo carmine; Kinetic study; Degradation pathway; Mechanism of oxidation
资金
- Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)
- Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)
- Financiadora de Estudos e Projetos (FINEP)
The kinetics and pathways associated with the photo-Fenton oxidation of indigo carmine (IC; 50 mg L-1) have been determined and compared with those of the Fenton, H2O2/UV-C and direct UV-C processes. The most efficient removal of total organic carbon (75 % in 60 min) was obtained with Fe2+ at 4 mmol L-1 and H2O2/Fe2+ ratio of 6:1. Examination of the kinetics of these four advanced oxidation processes (AOPs) indicated that the degradation of IC involves a rapid step (0-1 min) and a slow step (1-60 min) with both presenting significant differences regarding reaction rates. In the photo-Fenton process, the effect of Fe2+ concentration on the kinetic constant was significantly higher than that of H2O2/Fe2+ ratio, while the excess of H(2)O(2 )reduced the reaction rate. The effects of these parameters on the kinetic constant of the slow step were best described by an integrated pseudo second-order model. Photo-Fenton and Fenton processes were more efficient than H2O2/UV-C and direct UV-C in terms of complete mineralization as demonstrated by the mass spectra obtained after each treatment. The mechanisms involved in the mineralization of IC by the tested AOPs were characterized by the action of OH center dot and UV-C radiation and comprised abstraction of electrons, OH center dot and H-center dot as well as substitution, electron displacement and addition reactions. Furthermore, the rapid step was associated mainly with the breakdown of chromophore groups, while the slow step involved mineralization of aromatic rings and carbon abstractions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据