Photocatalytic Purification of Wastewater Polluted by Odorant Sulfur Compounds Using Titanium Oxide in a Continuous Photoreactor

2013 ◽  
Vol 11 (1) ◽  
pp. 561-567 ◽  
Author(s):  
Mohammad Reza Toosi ◽  
Mohamad Hasan Peyravi ◽  
Jafar Sajadi ◽  
Mohamad J. Bayani ◽  
Hadi Manghabati
Keyword(s):  
Waste Water ◽  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Titanium Oxide ◽  
Efficient Method ◽  
Ex Situ ◽  
Photocatalytic Decomposition ◽  
Methyl Ethyl ◽  
Photocatalytic Process ◽  
Initial Concentration

Abstract Using titanium dioxide, photocatalytic degradation of waste water polluted by commercial mercaptans (80% t-butyl mercaptan and 20% methyl ethyl sulfide) was investigated in a continuous photoreactor in the presence of UV irradiation. The reaction was performed at different pH of solution, intensity of irradiation, and initial concentration of odorant. Kinetics and mechanism of photocatalytic decomposition of mercaptans were studied by ex situ FTIR measurements of intermediates. The results showed that the photocatalytic process for degradation of mercaptans was an efficient method for mineralization of sulfur odorants in waste water. A proposed mechanism of mineralization of mercaptan was presented based on the results.

Use of Experimental Designs to Establish a Kinetic Law for a Gas Phase Photocatalytic Process

2014 ◽  
Vol 12 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Cécile Raillard ◽  
Audrey Maudhuit ◽  
Valérie Héquet ◽  
Laurence Le Coq ◽  
Jean Sablayrolles ◽  
...  
Keyword(s):  
Light Intensity ◽  
Photocatalytic Degradation ◽  
Gas Phase ◽  
Photocatalytic Oxidation ◽  
Experimental Designs ◽  
Photocatalytic Process ◽  
Air Velocity ◽  
Kinetic Rate ◽  
Initial Concentration ◽  
Designs Of Experiments

Abstract The photocatalytic degradation of three common indoor VOCs – acetone, toluene and heptane – is investigated in a dynamic photocatalytic oxidation loop using Box–Behnken designs of experiments. Thanks to the experimental results and the establishment of a kinetic rate law based on a simplified mechanism, a predictive model for the VOC degradation involving independent factors is developed. The parameters under investigation are initial concentration, light intensity and air velocity through the photocatalytic medium. The obtained model fits properly the experimental curves in the range of concentration, light intensity and air flow studied.

scholarly journals Kinetics of atrazine degradation by photocatalytic process in aqueous solution

2003 ◽  
Vol 5 (2) ◽  
pp. 87-93 ◽  
Author(s):  
O. Zahraa ◽  
L. Sauvanaud ◽  
G. Hamard ◽  
M. Bouchy
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Salicylic Acid ◽  
Photocatalytic Degradation ◽  
Competitive Adsorption ◽  
Initial Time ◽  
Photocatalytic Process ◽  
Herbicide Atrazine ◽  
Kinetics Of ◽  
Atrazine Degradation

The photocatalytic degradation of the herbicide atrazine has been studied using suspended titanium dioxide as catalyst. The Langmuir-Hinshelwood model is satisfactorily obeyed at initial time and in the course of the reaction. The rate of degradation is found to be enhanced by the addition of persulphate ions. Competitive degradation between atrazine and other pollutants is satisfactorily interpreted as monitored by a competitive adsorption of the reactants. As a consequence, efficient reactants such as salicylic acid and phenol delay atrazine degradation until these compounds are degraded.

Preparation of Visible Light Response K6SiW11O39SnII for Photocatalytic Degradation of Acid Brilliant Scarlet

2012 ◽  
Vol 476-478 ◽  
pp. 2005-2008
Author(s):  
Xiu Hua Zhu ◽  
Jia Huan Liu ◽  
Li Li Zhao ◽  
Peng Yuan Wang
Keyword(s):  
Aqueous Solution ◽  
Solar Radiation ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Light Response ◽  
Photocatalytic Decomposition ◽  
Initial Concentration ◽  
Environmental Friendly ◽  
Visible Light Response ◽  
Initial Ph

Environmental friendly materials, K6SiW11O39SnⅡ(abbreviated as SiWSn), was synthesized, which is visible light response photocatalyst. The photocatalytic decomposition of Acid Brilliant Scarlet (abbreviated as ABS) aqueous solution with SiWSn was investigated using a broad spectrum of solar radiation. The results showed that the photocatalytic degradation efficiency of ABS with SiWSn was affected by the initial pH of ABS solution, the amount of SiWSn and the photolysis time. When the initial pH of ABS solution was 5, the initial concentration of that (20mL) was 3mg L-1, the concentration of SiWSn was 1.25g L-1, and it was irradiated 4h under the sunlight, the discoloration rate of which was 71.4%.

Preparation Nano-Sized ZnO/Ag Particles and Photocatalytic Degradation of UDMH Wastewater

2014 ◽  
Vol 1015 ◽  
pp. 442-446 ◽  
Author(s):  
Ying Jia ◽  
Ya Nan He ◽  
Feng Hao Liang ◽  
Mei Yuan ◽  
Tian Tian Liu
Keyword(s):  
Waste Water ◽  
Quantum Yield ◽  
Photocatalytic Degradation ◽  
Crystallite Size ◽  
Hydrothermal Method ◽  
Light Sources ◽  
Photocatalytic Process ◽  
Spectral Absorption ◽  
Degradation Rates ◽  
Ag Particles

Different morphologies of nanoZnO have been synthesized by hydrothermal method and ethanol-assisted hydrothermal method, the quantum yield has been improved by noble metal doping, and also the range of spectral absorption has been widened. Then the products are used in the photocatalytic process of UDMH waste water. It is found that the crystallite size of the products is about 41~46nm, the maximum degradation rates of ZnO/Ag are 92.7% under the ultraviolet light, and 80.2% under the sunlight. The variation of the photocatalytic middle-product under different light sources is analyzed and it is found that the middle-product is decomposed more quickly and throughly under sunlight.

Titanium Dioxide Catalyzed Photocatalytic Degradation of Carboxylic Acids from Waste Water: A Review

2012 ◽  
Vol 712 ◽  
pp. 175-189 ◽  
Author(s):  
Vimal Gandhi ◽  
Manish Mishra ◽  
P.A. Joshi
Keyword(s):  
Waste Water ◽  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Carboxylic Acids ◽  
Chemical Process ◽  
Basic Mechanism ◽  
Heterogeneous Photocatalysis ◽  
Catalyst Loading ◽  
Process Industries ◽  
Chemical Process Industries

Among the new oxidation methods in advanced oxidation processes, heterogeneous photocatalysis based on UV/ titanium dioxide is one of the emerging technologies for degrading and totally mineralizing toxic and highly stable carboxylic acids from waste water has attracted great attention in last decade. The aliphatic and aromatic carboxylic acids are widely used as reactants or produced as main products or byproducts in various chemical process industries. These chemical process industries generates waste water containing significant amount of carboxylic acids, which need to be removed from waste water before disposal to natural water bodies due to the environmental restrictions and their hazardous effects on flora and fauna. This paper reviews photocatalytic degradation (PCD) process for various carboxylic acids in detail, including basic mechanism of titanium dioxide, effect of carboxylic acid structure and various reaction parameters like effect of initial concentration and kinetic study, catalyst loading, pH, adsorption and deactivation of the photocatalyst. A critical analysis of the available literature has been made and some general conclusions have been drawn related to the above mentioned parameters. The photocatalytic degradation pathways for carboxylic acids are also discussed to understand this process thoroughly.

Performance of Bi20TiO32 for Photocatalytic Degradation of Organic Pollutants in Water

2011 ◽  
Vol 233-235 ◽  
pp. 724-727
Author(s):  
Xu Hui Sun ◽  
Guo Hua Zhang ◽  
Lin Sun ◽  
Jun Ma
Keyword(s):  
Waste Water ◽  
Methyl Orange ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Surface Charge ◽  
Organic Pollutants ◽  
Light Wavelength ◽  
Photocatalytic Process ◽  
Optimum Ph ◽  
Light Activity

The factors that influence the performance of Bi20TiO32were discussed, and the removal of TOC in the analogue waste water was also examined. The shorter the light wavelength or the more the intensity, the more efficient the photocatalytic process. Different substance has different optimum pH for being photodegraded by photocatalyst Bi20TiO32, which may be related with its surface charge. Aeration have little benefit for decomposing the organics. Some organics like methyl orange and phenol can be photodegraded by Bi20TiO32completely. Bi20TiO32has visible-light activity for the degradation of organics.

scholarly journals NOx photocatalytic degradation on gypsum plates modified by TiO2-N,C photocatalysts

2015 ◽  
Vol 17 (3) ◽  
pp. 8-12 ◽  
Author(s):  
Magdalena Janus ◽  
Kamila Bubacz ◽  
Justyna Zatorska ◽  
Ewelina Kusiak-Nejman ◽  
Adam Czyżewski ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Photocatalytic Decomposition ◽  
Carbon And Nitrogen ◽  
Strength Tests ◽  
Different Types ◽  
Heating Up

Abstract In presented studies the photocatalytic decomposition of NOx on gypsum plates modified by TiO2-N,Cphotocatalysts were presented. The gypsum plates were obtained by addition of 10 or 20 wt.% of different types of titanium dioxide, such as: pure TiO2 and carbon and nitrogen co-modified TiO2 (TiO2-N,C) to gypsum. TiO2-N,C photocatalysts were obtained by heating up the starting TiO2 (Grupa Azoty Zakłady Chemiczne Police S.A) in the atmosphere of ammonia and carbon at the temperature: 100, 300 i 600ºC. Photocatalyst were characterized by FTIR/DRS, UVVis/DR, BET and XRD methods. Moreover the compressive strength tests of modified gypsum were also done. Photocatalytic activity of gypsum plates was done during NOx decomposition. The highest photocatalytic activity has gypsum with 20 wt.% addition of TiO2-N,C obtained at 300ºC.

The Effect of Different Ions on Photodegradation Rhodamine B in TiO2 Suspension Liquid

2013 ◽  
Vol 807-809 ◽  
pp. 2739-2742
Author(s):  
Peng Wei Huo ◽  
Mao Bin Wei ◽  
Xin Lin Liu ◽  
Dan Dan Wang ◽  
Zi Yang Lu ◽  
...  
Keyword(s):  
Waste Water ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Degradation Rate ◽  
Ph Value ◽  
Degradation Process ◽  
Photocatalytic Process ◽  
Negative Effect ◽  
Anions And Cations

The photocatalytic degradation process of waste water was usually influenced by many factors, such as different ions, addition reagent and pH value. In order to investigate the effect of ions strength in the photocatalytic process, the anions and cations were systematically investigated with P25 TiO2 photocatalyst with Rhodamine B (RB) as waste water in this work. The results showed that the cations of low valence showed minimum negative effect on degradation rate and the most anions showed enhance the degradation rate of RB. The ions strength showed random in the photocatalytic process.

Photocatalytic Degradation of Bisphenol A in Aqueous Suspensions of Titanium Dioxide

2012 ◽  
Vol 433-440 ◽  
pp. 172-177 ◽  
Author(s):  
Chen Zhong Jia ◽  
Qiao Yan Qin ◽  
Yan Xin Wang ◽  
Cai Xiang Zhang
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Kinetic Model ◽  
Bisphenol A ◽  
Photocatalytic Degradation ◽  
Rate Constant ◽  
Removal Rate ◽  
Mercury Vapor ◽  
Initial Concentration ◽  
Photocatalytic Removal

Photocatalytic degradation of bisphenol A in aqueous solution by UV-TiO2 was studied in self-made photocatalysis reactor. The results showed that BPA was degraded effectively in UV-TiO2 photocatalysis system, and the processe followed Langmuir-Hinshelwood kinetic model. When TiO2 was dosed at 1.0 g/L, air amount was 1.2 L/min, BPA initial concentration was 10 mg/L with pH=5.5, and irradiated by a 15 W low pressure mercury vapor discharge lamp, the removal rate of BPA was up to 97%, and BPA was completely removed in 80 min when pH≥9.5; The photocatalytic removal rate constant was strongly related to the above factors.

Photocatalytic degradation of MC-LR in water by the UV/TiO2/H2O2 process

2015 ◽  
Vol 16 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Wei-ying Li ◽  
Yao Liu ◽  
Xiu-li Sun ◽  
Feng Wang ◽  
Lin Qian ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Free Radicals ◽  
Synergistic Effect ◽  
Photocatalytic Degradation ◽  
Uv Irradiation ◽  
Removal Rate ◽  
Optimum Conditions ◽  
Initial Concentration ◽  
High Production

The ultraviolet (UV)/titanium dioxide (TiO2)/hydrogen peroxide (H2O2) process (UTHP) has been proven to be effective in removing organics because of its high production of free radicals. In this study, UTHP was further investigated for the photocatalytic degradation of microcystin-LR (MC-LR). Results showed that three mechanisms could realize MC-LR photocatalytic degradation using TiO2. H2O2 could effectively inhibit recombination and considerably improve the production of radicals and superoxides. From a correlation of the removal rate with the isomerization and decomposition of MC-LR under UV irradiation it was inferred that isomerization was crucial for MC-LR degradation during photocatalysis given the vulnerability of the exposed conjugated double bonds. The photocatalysis of MC-LR was apparently dependent on pH and MC-LR initial concentration. Under the optimum conditions of pH 3.5, 0.05 g/L TiO2, and 0.05 mmol/L H2O2, 100% MC-LR (308 μg/L) could be removed within 60 min. This process was accompanied by a synergistic effect during the initial 10 min.

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