Effects of KBr and KI on Photocatalytic Degradation of Dye W-7G with Nano-TiO2 as Catalyst

International Journal of Photoenergy ◽

10.1155/2021/6610093 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Chao Zou ◽

Qi-Jin Geng ◽

Jing-Tuo Zhu ◽

Chen Jing ◽

Wen Zhong ◽

...

Keyword(s):

Photocatalytic Degradation ◽

Inorganic Salt ◽

Ph Value ◽

Nano Tio2 ◽

Photocatalytic Reactor ◽

Theoretical Support ◽

Maximum Value ◽

Degradation Of Dyes ◽

Bubbling Fluidized Bed ◽

Alkaline Conditions

To investigate the influence of inorganic salt on the photocatalytic degradation, the effects of KBr and KI at various concentrations and pH values on the photocatalytic degradation of dye W-7G using nanoscaled titanium dioxide as photocatalyst in a bubbling fluidized bed photocatalytic reactor (BFBPR) were studied. The results indicated that the degradation apparent rate constant ( K app ) of the system with KI was clearly higher than that with KBr under acidic or alkaline conditions. And the maximum value of K app (0.01127) appeared at the KI concentration of 0.075 g L-1 with a pH value of 9.37, meaning the highest degradation efficiency. Furthermore, the possible mechanism of photocatalytic degradation of W-7G in the presence of KBr and KI was proposed, which could provide a theoretical support for the further study of inorganic salt effects on the photocatalytic degradation of dyes.

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Study on the Photocatalytic Degradation of Ammonia Nitrogen in Aquaculture Wastewater by Fe3+-Doped Nano-TiO2 under UV Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.2001 ◽

2012 ◽

Vol 476-478 ◽

pp. 2001-2004

Author(s):

Xiao Cai Yu ◽

Peng Fei Zhu ◽

Kui Sheng Song ◽

Dong Dong Hu ◽

Qian Du

Keyword(s):

Reaction Time ◽

Photocatalytic Degradation ◽

Uv Irradiation ◽

Volume Fraction ◽

Ph Value ◽

Removal Rate ◽

Ammonia Nitrogen ◽

Nano Tio2 ◽

Initial Concentration ◽

Aquaculture Wastewater

The Fe3+-doped nano-TiO2 catalyst with various amounts of dopant Fe3+ irons was prepared by a sol-gel method. The products were characterized by XRD and SEM. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Fe3+-doped nano-TiO2 under UV irradiation. In the experiment, the effect of Fe3+/TiO2 dosage, the ratio of dopant Fe3+, ammonia-N initial concentration, pH value, H2O2 volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. The experimental results can be stated as follows: when the ratio of dopant Fe3+ was 0.25% wt, the dosage of Fe3+/TiO2 was 0.7 g/L, the initial concentration of ammonia-N was 10 mg/L, H2O2 volume fraction was 4 %, respectively, if the reaction time may last 4 h, the removal rate of ammonia-N was expected to reach 97.17 %.

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Modeling the Solar Photocatalytic Degradation of Dyes

Journal of Solar Energy Engineering ◽

10.1115/1.2391255 ◽

2006 ◽

Vol 129 (1) ◽

pp. 87-93 ◽

Cited By ~ 7

Author(s):

H. I. Villafán-Vidales ◽

S. A. Cuevas ◽

C. A. Arancibia-Bulnes

Keyword(s):

Absorption Coefficient ◽

Photocatalytic Degradation ◽

Linear Trend ◽

Wavelength Region ◽

Radiation Absorption ◽

Polluted Water ◽

Photocatalytic Reactor ◽

Degradation Of Dyes ◽

Degradation Rates ◽

Photocatalytic Reactors

Background. The calculation of radiation absorption by the catalyst in solar photocatalytic reactors has been addressed by some authors, because it is a necessary step for the modeling of the detoxification of polluted water in these systems. Generally transparent pollutants have been considered, which somewhat simplifies the calculations. However, there has been an increasing interest in the study of solar photocatalytic degradation of dyes. These substances are not transparent to the radiation that the catalyst is able to absorb, and therefore their optical properties must be taken into account in the radiative modeling. Method of Approach. Absorption of radiation by the catalyst suspended in colored water is modeled by using the P1 approximation of radiative transfer theory. The absorption coefficient of the dye is taken into account in these calculations. A kinetic model is used to model degradation rates, based on the results of the radiative calculations. This has to be done through an Euler type method, because the reduction of dye concentration constantly modifies the optical conditions on the reactor, requiring a recalculation of radiation absorption at each step. Also, photocatalytic degradation experiments were carried out in a CPC solar photocatalytic reactor with tubular reaction space. Degradation of the Acid Orange 24 Azo dye was studied. The experimental degradation rates are compared with theoretical predictions. Results. An important influence of dye concentration is observed in the distribution of absorbed radiation, and also this parameter has a notorious effect on the predicted degradation rates. As a function of catalyst concentration, the degradation rate first increases rapidly and then at a smaller pace with an apparent linear trend. The experimental results can be reproduced well by the model. Conclusions. The proposed methodology allows modeling the solar photocatalytic degradation of dyes. The method should be applicable as long as the dye absorption coefficient is not too high in the wavelength region where the catalyst absorbs.

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Photooxidation Contribution Study on the Decomposition of Azo Dyes in Aqueous Solutions by VUV-Based AOPs

International Journal of Photoenergy ◽

10.1155/2011/156456 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 14

Author(s):

Chih-Ming Ma ◽

Gui-Bing Hong ◽

Hua-Wei Chen ◽

Nguyen-Thi Hang ◽

Yung-Shuen Shen

Keyword(s):

Azo Dyes ◽

Ph Value ◽

Reaction Rates ◽

Degradation Of Dyes ◽

Degradation Rates ◽

Effects Of Ph ◽

Alkaline Conditions ◽

Acidic Conditions ◽

High Concentrations ◽

Acid Blue

The effects of pH value, VUV intensity, initial dye concentration, initial H2O2concentration, and TiO2loading dose on the degradation of three azo dyes: acid Orange 8, acid Blue 29, and acid Blue 113 were studied to explore and compare the treatment efficiencies among the adopted AOPs. It was found that pH played an important role in the degradation of dyes using VUV irradiation. For VUV/H2O2, VUV/TiO2, and VUV/TiO2/H2O2processes, the decoloration rates of the three azo dyes were more efficient under acidic conditions relative to alkaline conditions. The degradation rates of dyes increased with increasing concentrations of H2O2, but reaction rates were retarded at high concentrations of H2O2because the H2O2compound acted as a scavenger of the hydroxyl radical. In this paper, three azo dyes were decomposed efficiently by VUV irradiation only demonstrating the effectiveness of VUV direct photolysis.

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Photocatalytic degradation of explosives contaminated water

Water Science & Technology ◽

10.2166/wst.2002.0729 ◽

2002 ◽

Vol 46 (11-12) ◽

pp. 139-145 ◽

Cited By ~ 11

Author(s):

S.-J. Lee ◽

H.-S. Son ◽

H.-K. Lee ◽

K.-D. Zoh

Keyword(s):

Photocatalytic Degradation ◽

Total Nitrogen ◽

Contaminated Water ◽

Ammonium Ions ◽

Nitrate Ion ◽

Photocatalytic Reactor ◽

Initial Concentration ◽

Initial Ph ◽

Alkaline Conditions ◽

The Impact

This study was undertaken to examine the degradation of TNT, RDX and HMX in a circular photocatalytic reactor with TiO2 as a photocatalyst. We examined the impact of parameters such as the initial concentration, initial pH of solution on rates of photocatalized transformation, and the mineralization. The results showed that photocatalysis is an effective process for the degradation of TNT, RDX and HMX. They could be completely degraded in 150 min with 1.0 g/L TiO2 at pH 7. An increase in the photocatalytic degradation of HMX was noticed with decreasing initial HMX. The rates of RDX and HMX degradation were greater in neutral pH than in acidic and alkaline conditions. In case of TNT degradation, the rate of degradation was the fastest at pH 11. Approximately 82% TOC decrease in the TNT degradation was achieved after 150 min, whereas TOC decrease in RDX and HMX was 24% and 59%, respectively. Nitrate, nitrite, and ammonium ions were detected as the nitrogen byproducts from the photocatalysis, and more than 50% of the total nitrogen was recovered as nitrate ion in every explosives.

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Preparation of Nano-TiO2 and Performance Study on Photocatalytic Degradation of Methylene Blue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.1040 ◽

2012 ◽

Vol 430-432 ◽

pp. 1040-1043

Author(s):

Jiang Liu ◽

Zheng Xian Ma ◽

Shuai Liang

Keyword(s):

Methylene Blue ◽

Photocatalytic Degradation ◽

Ph Value ◽

Raw Material ◽

Dye Wastewater ◽

Performance Study ◽

Water Addition ◽

Nano Tio2 ◽

Blue Solution ◽

And Performance

Experiment of photocatalytic degradation was conducted through using tetra-n-butyl titanate and ethyl alcohol as raw material, adopting sol-gol method to prepare photocatalyst of nano-TiO2 and using methylene blue solution as analogue dye wastewater. The influences of hydrolyzing temperature, PH value, different water addition, and different speed of adding drops were investigated, as well as the reuse rate of photocatalyst.

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