scholarly journals Photocatalytic degradation of Bisphenol A: Kinetic studies and determination of the reaction pathway

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Luis F. Garay Rodríguez ◽  
Brenda Zermeño ◽  
Karla Alejandra López De la O ◽  
Elisa Leyva ◽  
Edgar Moctezuma
Keyword(s):  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Reaction Rate ◽  
Reaction Pathway ◽  
Batch Reactor ◽  
Analytical Techniques ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Reaction Products ◽  
Uv Lamps

The photocatalytic degradation of BPA aqueous solutions with commercial TiO2 (Evonik P25) was carried out in a home-made batch reactor illuminated with four UV lamps (λmax= 365 nm) in order to determine the kinetic parameters of the reaction rate equation and to identify and quantify some of the most stable aromatic intermediate reaction products. Low concentration (20 ppm) BPA solutions were completely degraded and mineralized in less than three hours of reaction. Whereas, BPA aqueous solutions with concentration above 50 ppm are transformed in other chemical compounds in 6 hours of reaction and fully mineralized in 15 hours of reaction. Kinetic analysis of the experimental results of BPA concentration as a function of time indicated that this photocatalytic degradation process follows a LH-HW reaction rate law where the reaction order shift from zero order to first order as the reactant concentration is decreased. Analysis of the reaction samples by different analytical techniques indicated that BPA is mineralized via formation of hydroquinone, benzoquinone, benzene-triol, catechol, and phenol by two simultaneous reaction pathways.

Kinetics of the Ozonation of Tetrabromobisphenol-A in Wastewater

2011 ◽  
Vol 383-390 ◽  
pp. 2945-2950 ◽  
Author(s):  
Jie Zhang ◽  
Shi Long He ◽  
Mei Feng Hou ◽  
Li Ping Wang ◽  
Li Jiang Tian
Keyword(s):  
Rate Constants ◽  
Apparent Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Kinetic Studies ◽  
Tetrabromobisphenol A ◽  
First Order ◽  
Reaction Rate Constants ◽  
Pseudo First Order ◽  
Kinetics Of

The kinetics of TBBPA degradation by ozonation in semi-batch reactor was studied. The reaction rate constants of TBBPA with O3 and •OH were measured by means of direct ozone attack and competition kinetics, and the values of which were 6.10 l/(mol•s), 4.8×109 l/(mol•s), respectively. Results of kinetic studies showed that TBBPA degradation by ozonation under the different conditions tested followed the pseudo-first-order. The values of apparent rate constant of TBBPA degradation increased with the increase of ozone dosage and pH, but decreased with the increase of initial TBBPA concentration.

Photocatalytic Decomposition of Metoprolol and Its Intermediate Organic Reaction Products: Kinetics and Degradation Pathway

2016 ◽  
Vol 14 (3) ◽  
pp. 809-820 ◽  
Author(s):  
Alfonso Pinedo ◽  
Mariana López ◽  
Elisa Leyva ◽  
Brenda Zermeño ◽  
Benito Serrano ◽  
...  
Keyword(s):  
Uv Light ◽  
Reaction Pathway ◽  
Kinetic Studies ◽  
Initial Reaction Rate ◽  
Degradation Pathway ◽  
Photocatalytic Decomposition ◽  
Initial Reaction ◽  
Low Molecular Weight ◽  
Reaction Products ◽  
Constant Flow Rate

Abstract High purity metoprolol prepared by neutralization of an aqueous solution of metoprolol tartrate is efficiently mineralized to CO2 and water by photocatalysis with TiO2, UV light and a constant flow rate of oxygen. Since the tartrate anions were eliminated, all the HO• generated by photocatalysis reacted efficiently with the aromatic part of the medication. The reaction pathway includes two routes of degradation. The first one includes the transformation of metoprolol to hydroquinone via formation of 4-(2-methoxyethyl)phenol, 2-(4-hydroxyphenyl)ethanol and 4-hydroxybenzaldehyde. Metoprolol is also degraded directly to hydroquinone. Then, this aromatic compound is oxidized to 1,2,4-benzenetriol, which is rapidly oxidized to low molecular weight organic acids before being completely mineralized to CO2 and water. Kinetic studies indicated that the initial reaction rate of the degradation of metoprolol, 4-(2-methoxyethyl)phenol, 2-(4-hydroxyphenyl)ethanol and 4-hydroxybenzaldehyde is described by the LH-HW model.

scholarly journals Photocatalytic Degradation of Acid Yellow 36 Using Zinc Oxide Photocatalyst in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sajjad Khezrianjoo ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Photocatalytic Degradation ◽  
Catalyst Concentration ◽  
Heterogeneous Medium ◽  
Batch Reactor ◽  
Aqueous Media ◽  
Electrical Energy ◽  
Degradation Process ◽  
Active Species ◽  
Catalyst Loading ◽  
Order Of Magnitude

A detailed investigation of photocatalytic degradation of Acid Yellow 36 (AY36) has been carried out in aqueous heterogeneous medium containing ZnO as photocatalyst in a batch reactor. The effects of some parameters such as pH, catalyst loading, and ethanol concentration were examined. Solutions with initial concentration of 50 mg L−1 of dye, within the range of typical concentration in textile wastewaters, were treated at natural pH of 6.93 and catalyst concentration of 1 g L−1 after 180 min irradiation. Investigations on the active species indicated that hydroxyl radicals play the major role in the process. Experiments showed that the most efficient pH on the removal of the dye with photocatalytic degradation process was 8; however, acidic pH was favored for the dark surface adsorption. Electrical energy consumption per order of magnitude for photocatalytic degradation of AY36 has been also determined.

scholarly journals Photocatalytic Degradation of Ampicillin Using PLA/TiO2 Hybrid Nanofibers Coated on Different Types of Fiberglass

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 176 ◽  
Author(s):  
Constantin Bobirică ◽  
Liliana Bobirică ◽  
Maria Râpă ◽  
Ecaterina Matei ◽  
Andra Mihaela Predescu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Kinetic Studies ◽  
Electrospinning Technique ◽  
Edge Type ◽  
Photocatalytic Reactor ◽  
Hybrid Nanofibers ◽  
Different Types ◽  
Fiberglass Fabric

New photocatalytic membranes based on polylactic acid (PLA)/TiO2 hybrid nanofibers deposited on fiberglass supports were prepared and tested for the removal of ampicillin from aqueous solutions. The electrospinning technique was used to obtain hybrid nanofibers that were deposited on three types of fiberglass with different structures, resulting in three distinct photocatalytic membranes namely fiberglass fabric plain woven-type membrane, fiberglass mat-type membrane, and fiberglass fabric one-fold edge-type membrane. The results of the photocatalytic tests showed that the highest efficiency of ampicillin removal from aqueous solution is obtained with the fiberglass fabric plain woven-type membrane. Although it has been shown that the rate of photocatalytic degradation of ampicillin is high, being practically eliminated within the first 30 min of photocatalysis, the degree of mineralization of the aqueous solution is low even after two hours of photocatalysis due to the degradation of PLA from the photocatalytic membrane. The instability of PLA in the reactive environment of the photocatalytic reactor, evidenced by morphological, mineralogical and spectroscopic analyzes as well as by kinetic studies, is closely related to the structure of the fiberglass membrane used as a support for PLA/TiO2 hybrid nanofibers.

scholarly journals Photocatalytic Degradation of Bismarck Brown G Using Irradiated ZnO in Aqueous Solutions

2010 ◽  
Vol 7 (2) ◽  
pp. 540-544 ◽  
Author(s):  
Falah H. Hussein ◽  
Ahmed F. Halbus ◽  
Hussein A. K. Hassan ◽  
Wisam A. K. Hussein
Keyword(s):  
Zinc Oxide ◽  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Degradation Process ◽  
First Order ◽  
Photocatalytic Decolorization ◽  
First Order Kinetics ◽  
Decolorization Efficiency ◽  
Increasing Temperature

In this study, a homemade photoreactor equipped with 125w/542 high pressure mercury lamp as a source for near-UV radiation, was used for photocatalytic degradation of aqueous solutions of Bismarck brown G, (C18H20N8Cl2),4-[5-(2,4-Diamino-5-methylphenyl)diazenyl-2-methylphenyl] diazenyl -6-methylbenzol-1,3-diamin using zinc oxide. The disappearance of the original colored reactant concentrations with irradiation time was monitored spectrophotometrically by comparison with unexposed controls. It is noticed that the photocatalytic degradation process was high at the beginning and then decreased with time following pseudo first-order kinetics according to the Langmuir–Hinshelwood model. The effects of zinc oxide mass, dye concentration and temperature on photocatalytic decolorization efficiency (P.D.E.) were studied. P.D.E. reached 95.76% for Bismarck brown G after 50 minutes of irradiation at 293.15 K P.D.E. was found to increase with increasing temperature and the activation energy of photocatalytic degradation was calculated and found to be equal to 32±1 kJ mol-1.

scholarly journals Inspired Preparation of Zinc Oxide Nanocatalyst and the Photocatalytic Activity in the Treatment of Methyl Orange Dye and Paraquat Herbicide

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ghaida H. Munshi ◽  
Amal M. Ibrahim ◽  
Laila M. Al-Harbi
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Analytical Techniques ◽  
Degradation Process ◽  
Naturally Occurring ◽  
Uv Lamp ◽  
Degradation Of Methyl Orange

As the need to use green chemistry routes increases, environmentally friendly catalytic processes are a demand. One of the most important and abundant naturally occurring catalysts is chlorophyll. Chlorophyll is the first recognized catalyst; it is a reducing agent due to its electron-rich structure. The effects of spinach on the preparation of zinc oxide nanoparticles and the photocatalytic degradation of methyl orange and paraquat in sunlight and under a UV lamp and photocatalytic degradation in sunlight were studied. Different parameters of the catalytic preparation process and photocatalytic degradation process were studied. Characterization of differently prepared samples was carried out using different analytical techniques such as XRD, SEM, and EDX and finally the photocatalytic activity towards decomposition of methyl orange and paraquat.

scholarly journals High Photocatalytic Performance of Modified Bismuth Oxychloride Semiconductor under Sunlight

2021 ◽  
Vol 37 (4) ◽  
pp. 770-778
Author(s):  
Preeja. P. Thattil ◽  
A. Leema Rose
Keyword(s):  
Dye Degradation ◽  
Diffuse Reflectance Spectrum ◽  
Ultra Violet ◽  
Analytical Techniques ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Bet Surface Area ◽  
X Ray ◽  
Bismuth Oxychloride ◽  
Potential Applications

In recent years, the bismuth compounds have gained much interest due to their potential applications in the field of Photocatalysis. In our present work, Bismuth oxychloride Photocatalyst and Aluminium fluoride doped Bismuth oxychloride photocatalyst were synthesized by simple chemical methods using Bismuth nitrate pentahydrate as the precursor. The synthesized photocatalysts were characterized by different analytical techniques such as X-ray diffraction analyses, Ultra Violet –Diffuse reflectance spectrum, Field Emission – Scanning Electron Microscopy, Energy dispersive X-ray analyses,Fourier transform infrared spectroscopy studies and BET surface area analysis. The photocatalytic performances of the as-synthesized doped and undoped Bismuth oxychloride photocatalyst were tested towards the degradation of Acid green 1 dye. The parameters such as the effect of pH, catalyst concentration and initial dye concentration are optimized, and the kinetic studies are carried out for the photocatalytic dye degradation process. The experimental results showed that about 80% of the Acid green 1 dye got decolourized within 90 minutes by effective air purging under natural sunlight radiation in the presence of the AlF-BiOCl photocatalyst under optimized conditions.

scholarly journals Kinetics and mechanisms of EDTA photocatalytic degradation withTiO2under different experimental conditions

2001 ◽  
Vol 3 (4) ◽  
pp. 193-199 ◽  
Author(s):  
Paola A. Babay ◽  
Carina A. Emilio ◽  
Rosana E. Ferreyra ◽  
Eduardo A. Gautier ◽  
Raquel T. Gettar ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Degradation ◽  
Reaction Rate ◽  
Initial Rate ◽  
Uv Light ◽  
Degradation Process ◽  
Kinetic Regime ◽  
Experimental Conditions ◽  
Initial Ph ◽  
Limiting Values

The photocatalytic degradationof EDTA overTiO2has been analyzed to establish the influence of oxidants on the reaction rate, the nature of the intermediates and the kinetic regime. Degussa P-25 suspensions containing EDTA at initial pH 3 in different concentrations were irradiated under near UV light. A Langmuirian behavior was observed.O2at saturation concentrations was found to be crucial for EDTA degradation. The rapid depletion of EDTA was not accompanied by a corresponding TOC decrease, indicating formation of refractory intermediates. An enhancement in TOC reduction could be achieved by keeping pH constant or by hydrogen peroxide addition. Addition of Fe(III) caused a remarkable increase on the initial rate of EDTA consumption and also on TOC decrease. Changes in both parameters clearly increased under the simultaneous addition of Fe(III) andH2O2, until limiting values.Some of the possible intermediates of EDTA degradation were evaluated in the filtered solution. So far, glycine, ethylenediamine, ammonium, formaldehyde, and formic, iminodiacetic, oxalic, oxamic, glycolic and glyoxylic acids have been identified in different proportions, depending on the experimental conditions. Different degradationpathways are proposed. Inthe presence of Fe(III), photo-Fenton reactions would contribute also to the degradation process.

scholarly journals Aquation reaction of iminodiacetate complex of oxidovanadium(IV) with 2,2’-bipyridine induced by Fe(III) ions: Kinetic studies

2019 ◽  
Vol 44 (4) ◽  
pp. 300-306
Author(s):  
Joanna Drzeżdżon ◽  
Agnieszka Piotrowska-Kirschling ◽  
Lech Chmurzyński ◽  
Dagmara Jacewicz
Keyword(s):  
Aqueous Solutions ◽  
Computer Program ◽  
Rate Constants ◽  
Reaction Rate ◽  
Kinetic Studies ◽  
Reaction Rate Constants ◽  
Different Temperatures ◽  
Kinetics Of

The kinetics of the aquation reaction of the [VO(ida)(bipy)]·2H2O (VO(ida)(bipy)) complex (where ida = iminodiacetate anion and bipy = 2,2’-bipyridine) promoted by [Fe(H2O)6]3+ ions were investigated in aqueous solutions. Spectrophotometric studies were carried out at different temperatures in the range of 293.15–313.15 K. The concentration of the [Fe(H2O)6]3+ (Fe3+) ions was kept within the range of 2 × 10–4 to 8 × 10–4 mol L–1, and the concentration of VO(ida)(bipy) was 1 × 10–3 mol L–1. The values of the observable reaction rate constants were calculated based on the Glint computer program. Furthermore, the mechanism for the aquation of VO(ida)(bipy), induced by Fe(III) ions, has been proposed.

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