scholarly journals Kinetic Study of Congo-Red Photo-Catalytic Degradation in Aqueous Media Using Zinc Oxide as Photo Catalyst Under Led Light

2021 ◽  
Vol 9 (1) ◽  
pp. 20-24
Author(s):  
Shinwar A. Idrees ◽  
Raad N. Salih ◽  
Khalat Bashir ◽  
Aram A. Hamasaeed

The kinetic of photo catalytic degradation of Congo red dye using semiconductor in aqueous solution of ZnO has been studied. All photochemical experiments have been carried out in quartz photo cell 25ml capacity and the solvent used for all experiment was distilled water (D. W). The influence of temperature has been investigated as well. Spectrophotometric method was utilized for this work. Degradation kinetic has been done for absorption peak of Congo red at 497 nm and 344 nm. Different method was applied for this purpose, and the results show that the degradation of Congo red was first order at 497nm and zero order at 344 nm. The degradation of CR dye were increased by increasing temperature from 20 oC to 40 oC and then degreased at 50 oC and this is due to desorption that occur at the semiconductor surface while; in case of 10 oC the rate constant was higher than 20 oC. However, when changing the concentration the rate constant dose not changed regularly, this perhaps due to the fact that it does not follow the same order throughout the degradation process, and it does not obey Arrhenius law of activation energy.

2019 ◽  
Vol 70 (10) ◽  
pp. 3473-3476 ◽  
Author(s):  
Laura Cocheci ◽  
Lavinia Lupa ◽  
Aniela Pop ◽  
Aurelia Visa ◽  
Bianca Maranescu ◽  
...  

In the present study, a new compound was used for decontaminating water polluted by Congo Red dye. Phosphono-aminoacid-Cd(II) pendant groups grafted on a polymeric support was prepared using impregnation of a polymer support functionalized with phosphono-aminoacid groups with an aqueous solution of Cd(NO3)2x4H2O. The catalyst was characterized by Fourier transform infrared ray, scanning electron microscope, termogravimetric analysis UV-Vis spectroscopy. The results suggest that the studied material could efficiently be used as photocatalyst in the degradation process of waters containing organic dyes under UV-Vis light irradiation.


2020 ◽  
Vol 34 (1) ◽  
pp. 41-54
Author(s):  
Abdul Malik ◽  
Abbas Khan ◽  
Natasha Anwar ◽  
Muhammad Naeem

Desirable cost and removal effectiveness of the adsorbents can be obtained by the use and modification of agricultural waste products. Therefore, in this study rice husk (RH), rice husk char (RHC) and chemically modified rice husk char (CMRHC) were prepared and used as adsorbents for the removal of Congo Red dye from aqueous media under different experimental conditions. It was observed that the adsorption of Congo Red dye was not only affected with the types of adsorbents used but also with other experimental variables such as time, adsorbent dose, dye concentration, pH and temperature. Thermodynamics study indicated that the adsorption of Congo Red dye on the three adsorbents is spontaneous and exothermic process. Kinetics data showed that the adsorption of Congo Red dye on these adsorbents follow pseudo-second order model better than the pseudo-first order model. Equilibrium adsorption data were tested with Langmuir, Freundlich, and Temkin adsorption isotherm models. It was observed that the equilibrium data of RH and RHC were found best fit to the Langmuir adsorption isotherm model whereas that of CMRHC was best fit to the Freundlich and Temkin models. CMRHC showed better efficiency compared to both RH and RHC.   Bull. Chem. Soc. Ethiop. 2020, 34(1), 41-54. DOI: https://dx.doi.org/10.4314/bcse.v34i1.4


2019 ◽  
Vol 70 (10) ◽  
pp. 3473-3476 ◽  

In the present study, a new compound was used for decontaminating water polluted by Congo Red dye. Phosphono-aminoacid-Cd(II) pendant groups grafted on a polymeric support was prepared using impregnation of a polymer support functionalized with phosphono-aminoacid groups with an aqueous solution of Cd(NO3)2x4H2O. The catalyst was characterized by Fourier transform infrared ray, scanning electron microscope, termogravimetric analysis UV-Vis spectroscopy. The results suggest that the studied material could efficiently be used as photocatalyst in the degradation process of waters containing organic dyes under UV-Vis light irradiation. Keywords: photocatalysts, Congo Red azo dye, phosphono-aminoacid-Cd(II) groups


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