A Comparative Study on Photocatalytic Degradation of Pyridinium – Based Ionic Liquid by TiO2 and ZnO in Aqueous Solution

2019 ◽  
Vol 17 (9) ◽  
Author(s):  
Oualida Nour El Houda Kaabeche ◽  
Razika Zouaghi ◽  
Soraya Boukhedoua ◽  
Seyfeddine Bendjabeur ◽  
Tahar Sehili
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquid ◽  
Photocatalytic Degradation ◽  
Alkaline Medium ◽  
Kinetics Study ◽  
No Adsorption ◽  
Experimental Conditions ◽  
First Order ◽  
First Order Kinetics ◽  
Carbonate Ions

Abstract The photocatalytic degradation of hexylpyridinium bromide (HPyBr) from an aqueous solution was studied by focusing on comparison of the photoactivity of ZnO and TiO2 P25. The process was carried out under different experimental conditions. The results showed that there is no adsorption of pollutant by both catalysts in the dark. The efficiency of P25 Degussa and ZnO photocatalysts were compared, and the photocatalytic kinetics study showed that ZnO is more efficient than TiO2 P25. The HPyBr photodegradation was found to follow a pseudo-first order kinetics, and the higher rates constants were obtained at the alkaline medium for ZnO (pH = 11, kapp = 9.61 × 10–2 min−1) and at acidic medium for TiO2 P25 (pH = 3, kapp = 1.28 × 10–2 min−1). The Langmuir–Hinshelwood model was found suitable to explain the rate constant data for the ionic liquid degradation by both catalysts. The presence of carbonate ions at alkaline medium was found to reduce the HPyBr degradation for ZnO and to enhance the HPyBr degradation for TiO2, this enhancement in TiO2/CO32-/UV system was confirmed by the addition of •OH and hvb+ scavengers. According to TOC and COD results, HPyBr mineralization was faster in ZnO/UV system than in TiO2/UV system.

Photocatalytic Degradation of 4-Chlorophenol with a Novel α-Ga2O3

2011 ◽  
Vol 356-360 ◽  
pp. 1319-1322
Author(s):  
Bao Xiu Zhao ◽  
Li Na Zheng ◽  
Yuan Wei ◽  
Fan Yang
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Endocrine Disrupting Chemicals ◽  
Life Time ◽  
First Order ◽  
First Order Kinetics ◽  
Endocrine Disrupting ◽  
The Common ◽  
Main Factors

Chlorophenols is a kind of environmental endocrine disrupting chemicals (EDCs) and it is hard for the common methods to degrade or remove them, so how to decompose these pollutants has attracted researches’ attention. In this paper, a novel α-Ga2O3was used to degrade 4-chlorophenol via photocatalytic reaction and degradation kinetics was investigated. The effects of main factors, such as dosage of α-Ga2O3and pH of aqueous solution, on degradation were studied, and degradation kinetics was also established. Experimental results displayed that the optimal pH of aqueous solution was about 7.8 and almost 98% 4-chlorophenol was decomposed after 2 h, when the dosage of α-Ga2O3was 0.4 g and the initial concentration of 4-chlorophenol was 20 mg/L (V=200 ml). Photocatalytic degradation of 4-chlorophenol with α-Ga2O3abided by first-order kinetics and half-life time was 20.4 min.

scholarly journals Electro-photocatalytic degradation of amoxicillin using calcium titanate

2018 ◽  
Vol 16 (1) ◽  
pp. 949-955 ◽  
Author(s):  
Lvshan Zhou ◽  
Xiaogang Guo ◽  
Chuan Lai ◽  
Wei Wang
Keyword(s):  
Photocatalytic Degradation ◽  
Reaction Rate ◽  
Irradiation Time ◽  
Oxygen Demand ◽  
Reaction Rate Constant ◽  
Calcium Titanate ◽  
Experimental Conditions ◽  
Exponential Factor ◽  
First Order ◽  
First Order Kinetics

AbstractThe electro-photocatalytic degradation of amoxicillin in aqueous solution was investigated using single factor test by the potassium permanganate method for measuring the values of chemical oxygen demand (CODMn). Batch experiments were carried out successfully under different conditions, including initial amoxicillin concentration, calcium titanate dosage, pH, UV irradiation time, electrolyte and temperature. The experimental results show that there is a great difference between electro-photocatalytic and photocatalitic degradation. The maximum electro-photocatalytic degradation efficiency can increase to 79% under the experimental conditions of 200 mL amoxicillin solution (100 mg L-1) with 0.5 g calcium titanate by pH=3 for 120 min irradiation and 0.058 g sodium chloride as electrolyte at 318.5K. In addition, the reaction rate constant of 0.00848~0.01349 min-1, activation energy of 9.8934 kJ mol-1 and the pre-exponential factor of 0.5728 were obtained based on kinetics studies, indicating that the electro-photocatalytic reaction approximately followed the first-order kinetics model.

scholarly journals Photocatalytic degradation of sulfamethazine in aqueous solution using ZnO with different morphologies

2018 ◽  
Vol 5 (4) ◽  
pp. 171457 ◽  
Author(s):  
Zhigang Yi ◽  
Juan Wang ◽  
Tao Jiang ◽  
Qiong Tang ◽  
Ying Cheng
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Reaction System ◽  
Degradation Pathway ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Different Shapes ◽  
Pseudo First Order ◽  
Release Ratio

In this study, photocatalytic experiments of 20 mg l −1 sulfamethazine (SMN) in aqueous solution containing ZnO with different morphologies, tetra-needle-like ZnO (T-ZnO), flower-like ZnO (F-ZnO) and nanoparticles ZnO (P-ZnO), were performed. The results indicated that photocatalytic degradation of SMN was effective and followed the pseudo-first-order reaction, but the degree of SMN mineralization showed obvious differences using ZnO with different shapes. After 12 h irradiation, 86%, 71% and 50% of the initial total organic carbon was eliminated in SMN suspension containing T-ZnO, F-ZnO and P-ZnO, respectively. The release ratio of sulfur was close to 100% in the presence of T-ZnO, but reached to 86% and 67% in the presence of F-ZnO and P-ZnO, respectively. The release ratio of nitrogen was about 76%, 63% and 40% using T-ZnO, F-ZnO and P-ZnO as photocatalyst, respectively. The morphology of ZnO played an important role in determining its catalytic activity. Seven intermediates were observed and identified in the UV/T-ZnO reaction system by LC-MS/MS analysis, and a possible degradation pathway was proposed.

Kinetics Investigation of the Photocatalytic Degradation of Acid Blue 92 in Aqueous Solution Using Nanocrystalline Tio2 Prepared in an Ionic Liquid

2009 ◽  
Vol 34 (1) ◽  
pp. 55-76 ◽  
Author(s):  
Shahnaz Ghasemi ◽  
Sara Rahimnejad ◽  
Shahrbanoo Rahman Setayesh ◽  
Mohammad Hosseini ◽  
Mohammad Reza Gholami
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquid ◽  
Photocatalytic Degradation ◽  
Nanocrystalline Tio2 ◽  
Acid Blue

Mo3S4 Nanorod: An Effective Photocatalyst for the Degradation of Organic Dyes in Aqueous Solution

2019 ◽  
Vol 12 (1) ◽  
pp. 61-69
Author(s):  
Madima Ntakadzeni ◽  
William Wilson Anku ◽  
Penny Poomani Govender ◽  
Leelakrishna Reddy
Keyword(s):  
Aqueous Solution ◽  
Ethylenediaminetetraacetic Acid ◽  
Organic Dyes ◽  
Sodium Molybdate ◽  
Rhombohedral Phase ◽  
Molybdenum Sulfide ◽  
Energy Band Gap ◽  
Facile Hydrothermal Method ◽  
First Order ◽  
First Order Kinetics

Background: A molybdenum sulfide (Mo3S4) nanorod photocatalyst was synthesised through the facile hydrothermal method and applied in the degradation of Rhodamine B and Methyl Blue dyes under visible light irradiation. Methods: The Mo3s4 nanorod was synthesised using sodium molybdate, sodiumdiethyldithiolcarbonate and ethylenediaminetetraacetic acid as molybdenum and sulfur sources, and capping agent respectively. The photocatalyst was characterized by using XRD, FTIR, TEM, SEM, EDS and UV-Vis spectroscopies. Results: SEM result shows that the synthesised sample has a rod-like shape made up of several thin sheets. The XRD result revealed the Mo3S4 nanorod to exist in the Rhombohedral phase. The energy band gap of the sample was calculated to be 2.02 eV. The synthesised Mo3S4 nanorod showed great potential in the removal of both RhB and MB in aqueous solution. 85.46% and 99.78% removals of RhB and MB dyes respectively were achieved in 90 min. Conclusion: It was also observed that the photodegradation of both RhB and MB follows pseudo-first order kinetics, with apparent rate constants of 0.0089 min-1 and 0.0118 min-1 for RhB and MB respectively.

Photocatalytic Degradation of Acrylic Acid, Acrolein and Hydroquinone Using TiO2 under Simulated Solar Irradiation

2013 ◽  
Vol 781-784 ◽  
pp. 2129-2132 ◽  
Author(s):  
Yan Wen Gong ◽  
Xue Ni Cheng ◽  
Hong Xun Zhang
Keyword(s):  
Acrylic Acid ◽  
Photocatalytic Degradation ◽  
Nitrogen Doping ◽  
Solar Irradiation ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order ◽  
Simulated Solar Irradiation

Nitrogen doping TiO2was prepared and used to degrade acrolein wastewater under simulated solar irradiation acrylic acid. The results showed that the removal of acrolein, hydroquinone and acrylic acid were 0.73, 0.64, 0.26 after 4 hour degradation by TiO2/UV system. The degradation of acrolein, hydroquinone and acrylic acid using TiO2/UV system followed pseudo first-order kinetics. It results indicated that this proposed method can be useful for the pretreatment acrolein wastewater.

Thermal Degradation of Green Asparagus Texture

1997 ◽  
Vol 60 (3) ◽  
pp. 315-320 ◽  
Author(s):  
CARMEN RODRIGO ◽  
MIGUEL RODRIGO ◽  
SUSANA FISZMAN ◽  
TERESA SÁNCHEZ
Keyword(s):  
Single Point ◽  
Experimental Conditions ◽  
Cutting Resistance ◽  
First Order ◽  
First Order Kinetics ◽  
Press Method ◽  
The Wire ◽  
Shear Press ◽  
Kinetics Of ◽  
Green Asparagus

A cutting cell was developed to evaluate the texture of green asparagus by measuring its resistance to being cut with a wire. The cell was used in conjunction with a universal texturometer and improved on the single-point method of the Wilder fibrometer. Experimental conditions were determined for using the cell to measure the cutting resistance of asparagus subjected to different extents of heat treatment. Better discrimination between samples was obtained than with a Kramer cell. The fresh asparagus spears. were heated at temperatures between 70 and 100°C for different lengths of time and the kinetics of the degradation of texture was studied. A biphasic (two-component) behavior was observed with each component displaying first-order kinetics, The kinetic parameters calculated by measuring the texture with the wire cell (cutting at a position 5 em from the tip of the asparagus) were Eaa = 9.56 and Eab = 20.43 kcal/mol (activation energy for components A and B), and ka85 = 1.047 and kb85 = 0.057 min−1 (rate constants for A and B of asparagus heated at 85°C). When the texture was determined by measuring the shear force with a Kramer cell, the parameters estimated were Eaa = 23.41 and Eab = 18.32 kcal/mol, and ka85 = 0.25 and kb85 = 0.025 min−1 Both the wire cell cutting method and the Kramer shear-press method are suitable for evaluating the degree of thermal softening of green asparagus heated to temperatures between 70 and 100°C.

Über die Abnahme von Elektronenzentren in 60Co-γ-bestrahltem polykristallinem NaCl bei Adsorption von Gasen

1969 ◽  
Vol 24 (5) ◽  
pp. 796-802 ◽  
Author(s):  
J. R. Rabe ◽  
G. Joppien
Keyword(s):  
Sodium Chloride ◽  
Ionizing Radiation ◽  
Nitrogen Molecule ◽  
Color Centers ◽  
Experimental Conditions ◽  
Adsorbed Molecules ◽  
First Order ◽  
First Order Kinetics ◽  
Adsorption Of Gases

Abstract Ionizing radiation generates color centers in sodium chloride. On adsorption of gases on preir-radiated salt the concentration of electron centers decreases. Adsorbed azoethane partly decomposes forming nitrogen. About one to five electron centers disappear per nitrogen molecule formed depending on experimental conditions (temperature, amount of azoethane adsorbed and pretreatment of the salt). Electron centers disappear and nitrogen is formed with identical rates following first order kinetics. It is suggested that adsorbed molecules interacting with the surface cause electrons or holes to escape from their traps and eventually to recombine.

Aerobic oxidative N-dealkylation of secondary amines in aqueous solution catalyzed by rhodium porphyrins

2014 ◽  
Vol 18 (10n11) ◽  
pp. 937-943 ◽  
Author(s):  
Lin Yun ◽  
Ling Zhen ◽  
Zikuan Wang ◽  
Xuefeng Fu
Keyword(s):  
Aqueous Solution ◽  
Oxidation Reaction ◽  
Catalyst Deactivation ◽  
Secondary Amines ◽  
First Order ◽  
Rate Determining Step ◽  
First Order Kinetics ◽  
Biochemical Oxidation ◽  
Iminium Ion ◽  
Rhodium Porphyrins

N-dealkylation demonstrates an important biochemical oxidation reaction by cytochrome P450 and other monooxygenases. In this article, catalytic oxidative N-dealkylation of secondary amines was achieved using rhodium(III) tetra (p-sulfonato-phenyl) porphyrin (( TSPP ) Rh III ) in aqueous solution with oxygen as the sole oxidant. Addition of benzaldehyde to trap primary amine product inhibited catalyst deactivation and dramatically increased reaction turnover numbers (TONs). Substrate scope examination suggested the reaction was performed with a preference for bulkier secondary amines. Kinetic study exhibited first-order kinetics with regard of ( TSPP ) Rh III catalyst. Results from the Hammett study gave a ρ value of -1.38, suggesting formation of an iminium ion intermediate in the rate determining step.

scholarly journals Efficient degradation of naproxen by persulfate activated with zero-valent iron: performance, kinetic and degradation pathways

2020 ◽  
Vol 81 (10) ◽  
pp. 2078-2091
Author(s):  
Shuyu Dong ◽  
Xiaoxue Zhai ◽  
Ruobing Pi ◽  
Jinbao Wei ◽  
Yunpeng Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydroxyl Radical ◽  
Rate Constants ◽  
Zero Valent Iron ◽  
Degradation Pathways ◽  
First Order ◽  
First Order Kinetics ◽  
Degradation Rates ◽  
Initial Ph ◽  
Pseudo First Order

Abstract Degradation of naproxen (NAP) by persulfate (PS) activated with zero-valent iron (ZVI) was investigated in our study. The NAP in aqueous solution was degraded effectively by the ZVI/PS system and the degradation exhibited a pseudo-first-order kinetics pattern. Both sulfate radical (SO4•−) and hydroxyl radical (HO•) participate in the NAP degradation. The second-order rate constants for NAP reacting with SO4•− and HO• were (5.64 ± 0.73) × 109 M−1 s−1 and (9.05 ± 0.51) × 109 M−1 s−1, respectively. Influence of key parameters (initial pH, PS dosage, ZVI dosage, and NAP dosage) on NAP degradation were evaluated systematically. Based on the detected intermediates, the pathways of NAP degradation in ZVI/PS system was proposed. It was found that the presence of ammonia accelerated the corrosion of ZVI and thus promoted the release of Fe2+, which induced the increased generation of sulfate radicals from PS and promoted the degradation of NAP. Compared to its counterpart without ammonia, the degradation rates of NAP by ZVI/PS were increased to 3.6–17.5 folds and 1.2–2.2 folds under pH 7 and pH 9, respectively.

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