Factors affecting the kinetics of methyl orange reduction photosensitized by colloidal CdS

1993 ◽  
Vol 73 (1) ◽  
pp. 47-52 ◽  
Author(s):  
José Peral ◽  
Andrew Mills
2019 ◽  
Author(s):  
Chem Int

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.


Author(s):  
Zahia Benredjem ◽  
Karima Barbari ◽  
Imene Chaabna ◽  
Samia Saaidia ◽  
Abdelhak Djemel ◽  
...  

Abstract The Advanced Oxidation Processes (AOPs) are promising environmentally friendly technologies for the treatment of wastewater containing organic pollutants in general and particularly dyes. The aim of this work is to determine which of the AOP processes based on the Fenton reaction is more effective in degrading the methyl orange (MO) dye. The comparative study of the Fenton, photo-Fenton (PF) and electro-Fenton (EF) processes has shown that electro-Fenton is the most efficient method for oxidizing Methyl Orange. The evolution of organic matter degradation was followed by absorbance (discoloration) and COD (mineralization) measurements. The kinetics of the MO degradation by the electro-Fenton process is very rapid and the OM degradation rate reached 90.87% after 5 min. The influence of some parameters such as the concentration of the catalyst (Fe (II)), the concentration of MO, the current density, the nature and the concentration of supporting electrolyte was investigated. The results showed that the degradation rate increases with the increase in the applied current density and the concentration of the supporting electrolyte. The study of the concentration effect on the rate degradation revealed optimal values for the concentrations 2.10−5 M and 75 mg L−1 of Fe (II) and MO respectively.


2014 ◽  
Vol 38 (9) ◽  
pp. 4197-4203 ◽  
Author(s):  
Mrinmoy Misra ◽  
Pawan Kapur ◽  
Manoj Kumar Nayak ◽  
MadanLal Singla

Visible light induced photocatalytic mechanism of Au@Ag@ZnO core–shell nanostructure and kinetics of methyl orange (MO) photo degradation by ZnO, Au@ZnO, Au@Ag@ZnO and TiO2.


2019 ◽  
Author(s):  
Shahin Safavizadeh ◽  
Brina M. Montoya ◽  
Mohammed A. Gabr ◽  
Detlef R. U. Knappe

2017 ◽  
Vol 98 ◽  
pp. 325-335
Author(s):  
Yong Liu ◽  
Ming Huang ◽  
Yaohui You ◽  
Donghai Zhu ◽  
Xiaojing Fu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document