scholarly journals Photocatalytic Degradation of Aniline Using TiO2Nanoparticles in a Vertical Circulating Photocatalytic Reactor

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
F. Shahrezaei ◽  
Y. Mansouri ◽  
A. A. L. Zinatizadeh ◽  
A. Akhbari
Keyword(s):  
Photocatalytic Degradation ◽  
Catalyst Concentration ◽  
Irradiation Time ◽  
Effect Of Temperature ◽  
Photo Degradation ◽  
Photocatalytic Reactor ◽  
Operational Conditions ◽  
Uv Illumination ◽  
Petroleum Refinery Wastewater ◽  
Initial Ph

Photocatalytic degradation of aniline in the presence of titanium dioxide (TiO2) and ultraviolet (UV) illumination was performed in a vertical circulating photocatalytic reactor. The effects of catalyst concentration (0–80 mg/L), initial pH (2–12), temperature (293–323 K), and irradiation time (0–120 min) on aniline photodegradation were investigated in order to obtain the optimum operational conditions. The results reveal that the aniline degradation efficiency can be effectively improved by increasing pH from 2 to 12 and temperature from 313 to 323 K. Besides, the effect of temperature on aniline photo degradation was found to be unremarkable in the range of 293–313 K. The optimum catalyst concentration was about 60 mg/L. The Langmuir Hinshelwood kinetic model could successfully elucidate the effects of the catalyst concentration, pH, and temperature on the rate of heterogeneous photooxidation of aniline. The data obtained by applying the Langmuir Hinshelwood treatment are consistent with the available kinetic parameters. The activated energy for the photocatalytic degradation of aniline is 20.337 kj/mol. The possibility of the reactor use in the treatment of a real petroleum refinery wastewater was also investigated. The results of the experiments indicated that it can therefore be potentially applied for the treatment of wastewater contaminated by different organic pollutants.

scholarly journals Photocatalytic Degradation of Textile Dyeing Wastewater Using Titanium Dioxide and Zinc Oxide

2008 ◽  
Vol 5 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Abbas J. Attia ◽  
Salih H. Kadhim ◽  
Falah H. Hussein
Keyword(s):  
Activation Energy ◽  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Effect Of Temperature ◽  
Dyeing Wastewater ◽  
Textile Dyeing ◽  
Textile Factory ◽  
Textile Dyeing Wastewater

Photodegradation of a real textile dyeing wastewater taken from Hilla textile factory in Babylon Governorate, Iraq have been investigated. Photocatalytic degradation was carried out over suspensions of titanium dioxide or zinc oxide under ultraviolet irradiation. Photodegradation percentage was followed spectrophometrically by the measurements of absorbance at λmax equal to 380 nm. The rate of photodegradation increased linearly with time of irradiation when titanium dioxide or zinc oxide was used. A maximum color removal of 96% was achieved after irradiation time of 2.5 hours when titanium dioxide used at 303K and 82% color reduction was observed when zinc oxide used for the same period and at the same temperature. The effect of temperature on the efficiency of photodegradation of dyestuff was also studied. The activation energy of photodegradation was calculated and found to be equal to 21 ± 1 kJ mol-1 on titanium dioxide and 24 ± 1 kJ mol-1 on zinc oxide.

Modeling and Optimization of Photocatalytic Degradation of Methylene Blue Using Lanthanum Vanadate

2020 ◽  
Vol 1008 ◽  
pp. 97-103
Author(s):  
Mahmoud Samy ◽  
Mona G. Ibrahim ◽  
Mohamed Gar Alalm ◽  
Manabu Fujii
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Textile Industry ◽  
Degradation Process ◽  
Optimum Conditions ◽  
Photo Degradation ◽  
Operational Conditions ◽  
Degradation Rates ◽  
Effects Of Ph

Methylene blue (MB) is one of the commonly used dyes in the textile industry and can be used as a model pollutant for the textile industry wastewater. In this work, the photocatalytic degradation of MB by synthesized nanoparticles of lanthanum vanadate (LaVO4) was assessed. The effects of pH, initial MB concentration and catalyst dose on the removal performance of MB were investigated and measuring the optimum values of these operational conditions was performed using response surface methodology (RSM). Catalyst dose of 0.43 g/L, initial MB concentration of 5.0 mg/L, and pH of 6.86 were found to be the optimum conditions in reaction time of 60 min. A mathematical model was formed to relate the removal efficiency of MB to the aforementioned operating parameters. The removal efficiency of MB was 91% without any scavengers at a catalyst dose of 0.3 g/L, pH of 7 and initial MB concentration of 10 mg/L. The trapping experiments confirmed the participation of different reactive species in the photo-degradation process. The degradation rates of MB were 91%, 86%, 81%, 77.70% and 72% in five successive runs using LaVO4.

Aqueous Photocatalytic Oxidation of Doxycycline

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Deniss Klauson ◽  
Alissa Poljakova ◽  
Natalja Pronina ◽  
Marina Krichevskaya ◽  
Anna Moiseev ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Experimental Research ◽  
Photocatalytic Oxidation ◽  
Catalyst Concentration ◽  
Sol Gel ◽  
Fluidised Bed ◽  
Photocatalytic Reactor ◽  
Titania Coatings

AbstractThe experimental research into the aqueous photocatalytic oxidation of doxycycline, a tetracycline family antibiotic, was undertaken. The objective of the study was to ensure the feasibility of doxycycline photocatalytic degradation by UVA irradiated titania coatings on granulated media to be used in fluidised bed photocatalytic reactor and by slurries of P25, Evonik, as well as by visible light-sensitive sol-gel synthesized carbon-containing titania. The parameters influencing doxycycline oxidation, like catalyst concentration, initial doxycycline concentration and pH with P25 TiO

scholarly journals Synthesis and characterization of ternary chitosan–TiO2–ZnO over graphene for photocatalytic degradation of tetracycline from pharmaceutical wastewater

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Asadzadeh Patehkhor ◽  
Moslem Fattahi ◽  
Mohammadreza Khosravi-Nikou
Keyword(s):  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Sol Gel ◽  
Weight Ratio ◽  
Molar Ratio ◽  
Operational Parameters ◽  
Pharmaceutical Wastewater ◽  
Operational Conditions ◽  
Molar Ratios

AbstractVarious nanocomposites of TiO2–ZnO, TiO2–ZnO/CS, and TiO2–ZnO/CS–Gr with different molar ratios were synthesized by sol–gel and ultrasound-assisted methods and utilized under UV irradiation to enhance the photocatalytic degradation of tetracycline. Characterization of prepared materials were carried out by XRD, FT-IR, FE-SEM, EDX and BET techniques. The TiO2–ZnO with the 1:1 molar ratio supported with 1:2 weight ratio CS–Gr (T1‒Z1/CS1‒Gr2 sample) appeared as the most effective material at the optimized operational conditions including the tetracycline concentration of 20 mg/L, pH = 4, catalyst dosage of 0.5 g/L, and 3 h of irradiation time. As expected, the graphene had a significant effect in improving degradation results. The detailed performances of the T1‒Z1/CS1‒Gr2 were compared with ternary nanocomposites from EDX and BET results as well as from the degradation viewpoint. This novel photocatalyst can be effective in actual pharmaceutical wastewater treatment considering the applied operational parameters.

Photocatalytic degradation of explosives contaminated water

2002 ◽  
Vol 46 (11-12) ◽  
pp. 139-145 ◽  
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.

scholarly journals Photocatalytic Degradation of a Systemic Herbicide: Picloram from Aqueous Solution Using Titanium Oxide (TiO2) under Sunlight

2020 ◽  
Vol 4 (4) ◽  
pp. 58
Author(s):  
Md. Rakibul Islam ◽  
Jahida Binte Islam ◽  
Mai Furukawa ◽  
Ikki Tateishi ◽  
Hideyuki Katsumata ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Titanium Oxide ◽  
Irradiation Time ◽  
Degradation Mechanism ◽  
Chloride Ion ◽  
Reaction Rate Constant ◽  
Ammonium Ion ◽  
Light Reaction ◽  
First Order Kinetics ◽  
Initial Ph

The photocatalytic degradation of picloram (4-amino-3,5,6-trichloro-2-pyridincarboxylic acid), which is one of popular acidic herbicide, was investigated with the existence of titanium oxide (TiO2) under sunlight. The total photocatalytic degradation of 20 ppm of picloram was occurred within 30 min irradiation with TiO2, while a negligible degradation was found without TiO2 under sunlight. The influence of various parameters, like TiO2 dosage, solution initial pH, intensity of light, reaction temperature and irradiation time, was found during the photocatalytic degradation of picloram. The mineralization of picloram was proved by the deterioration of total organic carbon (TOC) of the photocatalytic process. The pseudo–first order kinetics of photocatalytic degradation was obtained according to the Langmuir–Hinshelwood model, and the reaction rate constant was 17.6 × 10−2 min−1. Chloride ion, ammonium ion, nitrate ion and CO2 were erected as the final products after completing the photocatalytic degradation of picloram. The intermediate products could not be determined by the GC–MS during the degradation of picloram. Therefore, the degradation mechanism of the picloram was proposed based on the frontier electron density and the point charge at each atom of the picloram molecule. The photocatalytic degradation method, using sunlight, may develop into as a pragmatic technique to purify picloram contaminated wastewater.

scholarly journals Enhanced Photocatalytic Degradation and Mineralization of Furfural Using UVC/TiO2/GAC Composite in Aqueous Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Bahram Ghasemi ◽  
Bagher Anvaripour ◽  
Sahand Jorfi ◽  
Neematollah Jaafarzadeh
Keyword(s):  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Irradiation Time ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Total Pore Volume ◽  
Operational Parameters ◽  
Experimental Conditions ◽  
First Order Kinetics ◽  
Initial Ph

Titanium dioxide nanoparticles were immobilized on granular activated carbon (GAC) as a porous and low-density support for photocatalytic degradation of furfural. The TiO2/GAC composite was synthetized using the simple sol-gel method and fully characterized. The effects of the operational parameters of furfural concentration (200–700 mg/L), initial pH (2–12), TiO2/GAC composite dosage (1–3.5 g/L), and irradiation time (20–120 min) were studied. The synthetized TiO2/GAC composite exhibited a total pore volume of 0.13 cm3/g and specific surface area of 35.91 m2/g. Removal efficiency of up to 95% was observed at initial pH of 10, TiO2/GAC dosage of 2.5 g/L, irradiation time of 80 min, and initial furfural concentration of 500 mg/L. The photocatalyst could be reused at least four consecutive times with a mere 2% decrease in furfural removal efficiency. Mineralization efficiency of 94% was obtained within 80 min. Pseudo-first-order kinetics best fit the photocatalytic degradation of furfural under experimental conditions.

scholarly journals Photocatalytic Degradation of Commercial Diazinon Pesticide Using C,N-codoped TiO2 as Photocatalyst

2020 ◽  
Vol 20 (3) ◽  
pp. 587
Author(s):  
Khoiriah Khoiriah ◽  
Diana Vanda Wellia ◽  
Jarnuzi Gunlazuardi ◽  
Safni Safni
Keyword(s):  
Aqueous Solution ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Catalyst Concentration ◽  
Irradiation Time ◽  
Low Energy ◽  
Initial Concentration ◽  
Codoped Tio2 ◽  
Initial Ph ◽  
Uv Visible

Diazinon (C12H21N2O3PS) is an effective pest controller that has been frequently used by farmers in agriculture. It is a nonspecific and highly toxic pesticide having low persistence in the environment and categorized as moderately hazardous class II. The degradation of commercial diazinon in aqueous solution was investigated by photocatalysis using low-energy activated C,N-codoped TiO2 as catalyst under visible-light. The influence of some parameters, i.e., catalyst concentration, the initial concentration of diazinon, initial pH of diazinon, and irradiation time on the diazinon degradation was studied. The amount of diazinon degradation was strongly influenced by all the above parameters. The results show that titania-modified enhanced the degradation percentage of diazinon, from 44.08% without a catalyst to 86.93% by adding 12 mg C,N-codoped TiO2 catalyst after 30 minutes visible-light irradiation. UV-visible spectrophotometer, HPLC, and COD analysis verified that diazinon was successfully degraded under photocatalysis visible.

scholarly journals ZnO Nanoparticles with Controllable Ce Content for Efficient Photocatalytic Degradation of MB Synthesized by the Polyol Method

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Gregorio Flores-Carrasco ◽  
Micaela Rodríguez-Peña ◽  
Ana Urbieta ◽  
Paloma Fernández ◽  
María Eugenia Rabanal
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Doping Concentration ◽  
Polyol Method ◽  
Transmission Microscopy ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Optical Luminescence ◽  
Pl Emission ◽  
Ce Content

This paper reports on the synthesis of Ce-doped ZnO (CZO) nanoparticles (NPs) by an alternative polyol method at low temperature. The method, facile and rapid, uses acetate-based precursors, ethylene glycol as solvent, and polyvinylpyrrolidone as capping agent. The effects of the Ce-doping concentration (ranging from 0 to 8.24 atomic%) on the structural, morphological, compositional, optical, luminescence, and photocatalytic properties of the NPs were investigated by several techniques. The structural findings confirmed that the CZO NPs have a typical hexagonal wurtzite-type structure with a preferred orientation along the (101) plane. The results obtained by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed that the NPs size decreased (from ~30 to ~16 nm) with an increase in the Ce-doping concentration. Energy Dispersive X-Ray Spectroscopy (EDS) and High Resolution Transmission Microscopy (HRTEM) results confirmed the incorporation of Ce ions into the ZnO lattice. Ce-doping influences the photoluminescence (PL) emission compared to that of pure ZnO. The PL emission is related to the presence of different kinds of defects, which could take part in charge transfer and/or trapping mechanisms, hence playing an essential role in the photocatalytic activity (PCA). In fact, in this work we report an enhancement of PCA as a consequence of Ce-doping. In this sense, the best results were obtained for samples doped with 3.24 atomic%, that exhibited a photocatalytic degradation efficiency close to 99% after 60 min ultraviolet (UV) illumination, thus confirming the viability of Ce-doping for environmental applications.

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