scholarly journals Evaluation of Kinetic Pseudo-Order in the Photocatalytic Degradation of Oflaxicin

2021 ◽  
Author(s):  
Giora Rytwo ◽  
Arye Lev Zelkind
Keyword(s):  
Heterogeneous Catalysis ◽  
Half Life ◽  
Advanced Oxidation Processes ◽  
Simple Procedure ◽  
Life Time ◽  
Degradation Process ◽  
Zero Order ◽  
Oxidation Processes ◽  
Kinetics Of Degradation ◽  
Kinetics Of

Ofloxacin is an extensively used efficient antibiotic. However, since it is a refractory pollutant, it is found in water sources, requiring methods to remove it from the environment. Advanced Oxidation Processes (AOPs) offer efficient alternatives since it yields complete degradation not achieved in adsorption or membrane processes. Kinetics of degradation process require monitoring the "pseu-do-order" of it to deliver evaluation of the proposed AOPs. Most studies assume ofloxacin degra-dation follows pseudo-first or -second order processes, whereas for full removal of refractory pol-lutants – lower pseudo-orders are required. This study presents a simple procedure to evaluate pseudo-orders of AOPs. Photolysis of 20 M ofloxacin follows pseudo-zero order, with half-life time (t1/2) of ~ 60 min. Very low TiO2 concentration in heterogeneous catalysis (0.2 mg L-1) has no in-fluence but increasing catalyst to 2.0 mg L-1 reduces t1/2 to 20 min, increasing pseudo-order to 0.8. Similar results are obtained with 2.0 mg L-1 H2O2 homogenous catalysis. Combining H2O2 with TiO2 reduces t1/2, but pseudo-order increases further (1.2). The conclusions are (1) ofloxacin can be ef-fectively degraded by both heterogenous and homogenous photocatalysis, (2) combined photoca-talysis yields higher pseudo-order, being less prone to achieve full removal, (3) analysis of specific pseudo-order in AOPs of refractory pollutants helps to further elucidate the efficiency of the process presented.

scholarly journals Evaluation of Kinetic Pseudo-Order in the Photocatalytic Degradation of Ofloxacin

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Giora Rytwo ◽  
Arye Lev Zelkind
Keyword(s):  
Half Life ◽  
Advanced Oxidation Processes ◽  
Degradation Kinetics ◽  
Simple Procedure ◽  
Life Time ◽  
Zero Order Kinetics ◽  
Low Concentrations ◽  
Antibiotic Drug ◽  
Kinetics Of ◽  
Additional Reduction

Ofloxacin is a highly efficient and widely used antibiotic drug. It is classified as a refractory pollutant due to its poor biodegradability. Consequently, it is commonly found in water sources, requiring efficient methods for its removal. Advanced oxidation processes (AOPs) offer efficient alternatives since those yield complete degradation not achieved in adsorption or membrane processes. Previous studies suggest ofloxacin degradation follows a pseudo-first or -second order processes, whereas for full removal of refractory pollutants—lower pseudo-orders are required. Monitoring the actual “pseudo-order” degradation kinetics of ofloxacin is needed to evaluate any proposed AOP process. This study presents a simple procedure to evaluate pseudo-orders of AOPs. Photolysis of 20 μM ofloxacin solutions follow pseudo-zero order kinetics, with half-life times (t1/2) of approx. 60 min. TiO2 heterogenous catalysts have been shown to have no influence at low concentrations (0.2 mg L−1), but a significant reduction of half-life time (t1/2 = 20 min) and increase in pseudo-order (0.8) is measured at 2.0 mg L−1. Similar results are obtained with homogenous catalysis by 2.0 mg L−1 H2O2. The combination of H2O2 and TiO2 catalysts shows additional reduction in half-time life with increase in the pseudo-order to 1.2. The conclusions are (1) heterogenous and homogenous photocatalysis can effectively degrade ofloxacin, (2) combined photocatalysis yields higher pseudo-order, being less prone to achieve full removal, and (3) analysis of specific pseudo-orders in AOPs of refractory pollutants helps to further elucidate the efficiency of the processes.

Evaluation of Kinetic Pseudo-Order in the Photocatalytic Degradation of Oflaxicin

2021 ◽  
Author(s):  
Giora Rytwo ◽  
Arye Lev Zelkind
Keyword(s):  
Half Life ◽  
Advanced Oxidation Processes ◽  
Degradation Kinetics ◽  
Simple Procedure ◽  
Life Time ◽  
Zero Order Kinetics ◽  
Antibiotic Drug ◽  
Heterogenous Catalyst ◽  
Kinetics Of ◽  
Additional Reduction

Ofloxacin is a highly efficient and widely used antibiotic drug. It is classified as a refractory pollutant due to its poor biodegradability. Consequently, it is commonly found in water sources, requiring efficient methods for its removal. Advanced Oxidation Processes (AOPs) offer efficient alternatives since those yield complete degradation not achieved in adsorption or membrane processes. Previous studies suggest ofloxacin degradation follows a pseudo-first or -second order processes, whereas for full removal of refractory pollutants – lower pseudo-orders are required. Monitoring the actual “pseudo-order” degradation kinetics of ofloxacin is needed to evaluate any proposed AOP process. This study presents a simple procedure to evaluate pseudo-orders of AOPs. Photolysis of 20 mM ofloxacin solutions follow pseudo-zero order kinetics, with half-life times (t1/2) of approx. 60 min. TiO2 heterogenous catalyst show to have no influence at low concentration (0.2 mg L-1) but a significant reduction of half-life time (t1/2 = 20 min) and increase in pseudo-order (0.8) is measured at 2.0 mg L-1. Similar results are obtained with homogenous catalysis by 2.0 mg L-1 H2O2. The combination of H2O2 and TiO2 catalysts shows additional reduction in half-time life with increase in the pseudo-order to 1.2. The conclusions are (1) heterogenous and homogenous photocatalysis can effectively degrade ofloxacin, (2) combined photocatalysis yields higher pseudo-order, being less prone to achieve full removal, (3) analysis of specific pseudo-orders in AOPs of refractory pollutants helps to further elucidate the efficiency of the processes.

scholarly journals Kinetics and Mechanistic Studies of Photochemical and Oxidative Stability of Galaxolide

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1813
Author(s):  
Aneta Sokol ◽  
Artur Ratkiewicz ◽  
Iwona Tomaszewska ◽  
Joanna Karpinska
Keyword(s):  
Advanced Oxidation Processes ◽  
Degradation Products ◽  
Advanced Oxidation ◽  
Degradation Process ◽  
Oh Radicals ◽  
Direct Photolysis ◽  
Oxidation Processes ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Oxidative Agents

Studies on kinetics of galaxolide (HHCB) degradation under influence of UV, simulated sunlight and some advanced oxidation processes (H2O2, UV/H2O2, and Vis/H2O2) were conducted. Galaxolide appeared to be a photolabile compound. The first-order kinetics model was assumed for all studied processes. It was observed that basic pH favored HHCB degradation. The influence of natural matrices (river water and artificial sweat) on direct photolysis of HHCB was examined. It was stated that the process of the photodegradation proceeded slower at the presence of each matrix. HHCB lactone was identified using the GC-MS technique. The recorded chromatograms showed that apart from the lactone, other degradation products were formed that we could not identify. In order to deeper understand the HHCB degradation process, DFT calculations were performed. The results pointed out that OH radicals play a key role in HHCB decomposition, which mainly proceeds via H abstractions as well as OH additions. It follows from the calculations that the visible light is sufficient to initiate the advanced oxidation processes (AOPs) under the oxidative conditions, whereas UV irradiation is needed to start decay with no oxidative agents.

scholarly journals Kinetics of Degradation of Eosin Y by One of the Advanced Oxidation Processes (AOPs)—Fenton’s Process

2016 ◽  
Vol 07 (12) ◽  
pp. 863-879 ◽  
Author(s):  
Ashraf Hossain ◽  
A. B. M. Sadique Rayhan ◽  
Md. Jahir Raihan ◽  
Aklima Nargis ◽  
Iqbal M. I. Ismail ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Eosin Y ◽  
Oxidation Processes ◽  
Kinetics Of Degradation ◽  
Kinetics Of ◽  
Fenton's Process

Comparative investigation on the removal of methyl orange from aqueous solution using three different advanced oxidation processes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zahia Benredjem ◽  
Karima Barbari ◽  
Imene Chaabna ◽  
Samia Saaidia ◽  
Abdelhak Djemel ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Current Density ◽  
Advanced Oxidation Processes ◽  
Degradation Rate ◽  
Supporting Electrolyte ◽  
Advanced Oxidation ◽  
Comparative Investigation ◽  
Oxidation Processes ◽  
The Comparative Study ◽  
Kinetics Of

Abstract The Advanced Oxidation Processes (AOPs) are promising environmentally friendly technologies for the treatment of wastewater containing organic pollutants in general and particularly dyes. The aim of this work is to determine which of the AOP processes based on the Fenton reaction is more effective in degrading the methyl orange (MO) dye. The comparative study of the Fenton, photo-Fenton (PF) and electro-Fenton (EF) processes has shown that electro-Fenton is the most efficient method for oxidizing Methyl Orange. The evolution of organic matter degradation was followed by absorbance (discoloration) and COD (mineralization) measurements. The kinetics of the MO degradation by the electro-Fenton process is very rapid and the OM degradation rate reached 90.87% after 5 min. The influence of some parameters such as the concentration of the catalyst (Fe (II)), the concentration of MO, the current density, the nature and the concentration of supporting electrolyte was investigated. The results showed that the degradation rate increases with the increase in the applied current density and the concentration of the supporting electrolyte. The study of the concentration effect on the rate degradation revealed optimal values for the concentrations 2.10−5 M and 75 mg L−1 of Fe (II) and MO respectively.

scholarly journals Degradation of the pharmaceuticals lamivudine and zidovudine using advanced oxidation processes

2020 ◽  
Vol 42 ◽  
pp. e9
Author(s):  
Alex Leandro Andrade de Lucena ◽  
Daniella Carla Napoleão ◽  
Hélder Vinícius Carneiro da Silva ◽  
Rayany Magali da Rocha Santana ◽  
Beatriz Galdino Ribeiro ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Oxidation Processes ◽  
First Order ◽  
Input Variables ◽  
Pharmaceutical Degradation ◽  
Uv C

The existence of pharmaceuticals in nature is a growing environmental problem, turning necessary the use of efficient treatments for the degradation of these substances, as the advanced oxidation processes (AOPs). In this work the AOPs UV/H2O2 and photo-Fenton were applied to degrade the pharmaceuticals lamivudine and zidovudine in an aqueous solution using a bench reactor, composed of three UV-C lamps. It was verified that the UV/H2O2 process presented a degradation of 97.33 ± 0.14% for lamivudine and 93.90 ± 0.33% for zidovudine, after 180 min of treatment and for an initial concentratin of each pharmaceutical of  5 mg.L-1 and [H2O2] of 600 mg.L-1.  A methodology by artificial neural networks (ANNs) was used to model the photocatalytic process, with the MLP 7-23-2 ANN representing it well, and determining the relative importance (%) of each of the input variables for the pharmaceutical’s degradation process. Kinetic studies for the pharmaceutical degradation and the conversion of organic matter showed good adjustments to the pseudo first-order models with R2 raging from 0.9705 to 0.9980. Toxicity assays for the before treatment solution indicated that the seeds Lactuca sativa and Portulaca grandiflora showed growth inhibition whereas the post-treatment solution inhibited only the growth of Lactuca sativa.

Degradation of propoxycarbazone-sodium with advanced oxidation processes

2011 ◽  
Vol 11 (1) ◽  
pp. 129-134 ◽  
Author(s):  
A. Dulov ◽  
N. Dulova ◽  
Y. Veressinina ◽  
M. Trapido
Keyword(s):  
Rate Constants ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Fenton Process ◽  
Oxidation Processes ◽  
First Order ◽  
Order Rate ◽  
Conversion Time ◽  
Pseudo First Order ◽  
Kinetics Of

The degradation of propoxycarbazone-sodium, an active component of commercial herbicide, in aqueous solution with ozone, UV photolysis and advanced oxidation processes: O3/UV, O3/UV/H2O2, H2O2/UV, and the Fenton process was studied. All these methods of degradation proved feasible. The kinetics of propoxycarbazone-sodium degradation in water followed the pseudo-first order equation for all studied processes except the Fenton treatment. The application of schemes with ozone demonstrated low pseudo-first order rate constants within the range of 10−4 s−1. Addition of UV radiation to the processes improved the removal of propoxycarbazone-sodium and increased the pseudo-first order rate constants to 10−3 s−1. The Fenton process was the most efficient and resulted in 5 and 60 s of half-life and 90% conversion time of propoxycarbazone-sodium, respectively, at 14 mM H2O2 concentration. UV treatment and the Fenton process may be recommended for practical application in decontamination of water or wastewater.

Modeling Kinetics of Illuminated and Dark Advanced Oxidation Processes

1996 ◽  
Vol 122 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Andrew Hong ◽  
Mark E. Zappi ◽  
Chiang Hai Kuo ◽  
Donald Hill
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Oxidation Processes ◽  
Kinetics Of

Progress in Characterization of Sludge Particles

1993 ◽  
Vol 28 (1) ◽  
pp. 145-148 ◽  
Author(s):  
E. Friedrich ◽  
H. Friedrich ◽  
W. Heinze ◽  
K. Jobst ◽  
H.-J. Richter ◽  
...  
Keyword(s):  
Surface Charge ◽  
Size Distribution ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Degradation Process ◽  
Laser Diffraction ◽  
Kinetics Of Degradation ◽  
Kinetics Of

The studies aimed at examining the influences of the particle size distribution and surface charge on the behaviour of sludge in dewatering. It was possible to show that defined size dispersions of sludge particles as well as surface charge are necessary to reach better dewatering results and that the found correlations were independent of the type of sludge and the sewage treatment plant (Friedrich et al., 1990 and 1991). Based on laser diffraction measurements to determine panicle size distribution it was found that it was necessary to set a specific proportion between fine and large sludge particles in order to produce the best possible dewatering results and to get the required shear resistant flocs. To characterize the surface charge of the sludge particles various measuring methods were used. Determining the zeta-potential is a suitable means to describe the kinetics of degradation process in the sludge.

scholarly journals Kinetics of photocatalytic removal of imidacloprid from water by advanced oxidation processes with respect to nanotechnology

2019 ◽  
Vol 17 (2) ◽  
pp. 254-265 ◽  
Author(s):  
A. Derbalah ◽  
M. Sunday ◽  
R. Chidya ◽  
W. Jadoon ◽  
H. Sakugawa
Keyword(s):  
Organic Carbon ◽  
Advanced Oxidation Processes ◽  
Catalyst Concentration ◽  
Irradiation Time ◽  
Formation Rate ◽  
Advanced Oxidation ◽  
Water Type ◽  
Oxidation Processes ◽  
Photocatalytic Removal ◽  
Kinetics Of

Abstract In this study, the kinetics of photocatalytic removal of imidacloprid, a systemic chloronicotinoid insecticide, from water using two advanced oxidation systems (ZnO(normal)/H2O2/artificial sunlight and ZnO(nano)/H2O2/artificial sunlight) were investigated. Moreover, the effects of pH, insecticide concentration, catalyst concentration, catalyst particle size, and water type on the photocatalytic removal of imidacloprid were evaluated. Furthermore, total mineralization of imidacloprid under these advanced oxidation systems was evaluated by monitoring the decreases in dissolved organic carbon (DOC) concentrations and formation rate of inorganic ions (Cl− and NO2−) with irradiation time using total organic carbon (TOC) analysis and ion chromatography to confirm the complete detoxification of imidacloprid in water. The degradation rate of imidacloprid was faster under the ZnO(nano)/H2O2/artificial sunlight system than the ZnO(normal)/artificial sunlight system in both pure and river water. The photocatalytic degradation of imidacloprid under both advanced oxidation systems was affected by pH, catalyst concentration, imidacloprid concentration, and water type. Almost complete mineralization of imidacloprid was only achieved in the ZnO(nano)/H2O2/artificial sunlight oxidation system. The photogeneration rate of hydroxyl radicals was higher under the ZnO(nano)/H2O2/artificial sunlight system than the ZnO(normal)/H2O2/artificial sunlight system. Advanced oxidation processes, particularly those using nanosized zinc oxide, can be regarded as an effective photocatalytic method for imidacloprid removal from water.

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