scholarly journals Removal of Reactive Green Dye from Textile Waste Water by Photo Fenton Process: Modeling, Kinetic, and Thermodynamic.

2021 ◽  
Vol 24 (2) ◽  
pp. 104-111
Author(s):  
Tabarek Abdulsajad Jabar ◽  
Khalid M. Mousa Al-zobai
Keyword(s):  
Reaction Kinetic ◽  
Oxidation Process ◽  
Irradiation Time ◽  
Fenton Process ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Hoff Equation ◽  
Textile Waste Water ◽  
Maximum Decolorization

This work investigated the removal of the reactive green (R.G) dye from wastewater using the photo-Fenton process. Batch experiments were carried out to research the role of the Impacts of operating parameters. The dosage of H2O2; dosage Fe+2; pH; temperature, and irradiation time were examined. Maximum decolorization efficiencies green dye were achieved at the [H2O2]=100 ppm; [Fe2+]=20 ppm; pH 3; temperature=56 °C and irradiation time=90 min. This research focuses on modeling, kinetics and thermodynamics of the removal of pollutant (reactive green dye) of water. The results showed that the decolorization kinetic of R.G followed pseudo-first-order reaction kinetic. Also the thermodynamic parameters ∆G˚, ∆H˚ and ∆S˚ were determined using the Van't Hoff equation for the oxidation processes. The changes in Gibbs free energy showed the oxidation process under normal conditions is non-spontaneous.

Superiority of solar Fenton oxidation over TiO2 photocatalysis for the degradation of trimethoprim in secondary treated effluents

2013 ◽  
Vol 67 (6) ◽  
pp. 1260-1271 ◽  
Author(s):  
I. Michael ◽  
E. Hapeshi ◽  
C. Michael ◽  
D. Fatta-Kassinos
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Heterogeneous Photocatalysis ◽  
Solar Irradiation ◽  
Fenton Process ◽  
Iron Salt ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Initial Substrate ◽  
Initial Substrate Concentration

The overall aim of this work was to examine the degradation of trimethoprim (TMP), which is an antibacterial agent, during the application of two advanced oxidation process (AOP) systems in secondary treated domestic effluents. The homogeneous solar Fenton process (hv/Fe2+/H2O2) and heterogeneous photocatalysis with titanium dioxide (TiO2) suspensions were tested. It was found that the degradation of TMP depends on several parameters such as the amount of iron salt and H2O2, concentration of TiO2, pH of solution, solar irradiation, temperature and initial substrate concentration. The optimum dosages of Fe2+ and H2O2 for homogeneous ([Fe2+] = 5 mg L−1, [H2O2] = 3.062 mmol L−1) and TiO2 ([TiO2] = 3 g L−1) for heterogeneous photocatalysis were established. The study indicated that the degradation of TMP during the solar Fenton process is described by a pseudo-first-order reaction and the substrate degradation during the heterogeneous photocatalysis by the Langmuir–Hinshelwood kinetics. The toxicity of the treated samples was evaluated using a Daphnia magna bioassay and was finally decreased by both processes. The results indicated that solar Fenton is more effective than the solar TiO2 process, yielding complete degradation of the examined substrate within 30 min of illumination and dissolved organic carbon (DOC) reduction of about 44% whereas the respective values for the TiO2 process were ∼70% degradation of TMP within 120 min of treatment and 13% DOC removal.

UV Based Advanced Oxidation Process for Degradation of Ciprofloxacin: Reaction Kinetics, Effects of Interfering Substances and Degradation Product Identification

2021 ◽  
Author(s):  
Bijoli Mondal ◽  
Shib Sankar Basak ◽  
Arnab Das ◽  
Sananda Sarkar ◽  
Asok Adak
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Degradation Products ◽  
Irradiation Time ◽  
Advanced Oxidation ◽  
Quantum Yields ◽  
Photon Flux ◽  
First Order

Abstract In the photochemical UV-H2O2 advanced oxidation process, H2O2 absorbs UV light and is decomposed to form hydroxyl radicals (OH·), which are highly excited and reactive for electron-rich organic compounds and hence can degrade organic compounds. In the present work, the UV-H2O2 process was investigated to degrade ciprofloxacin (CIP), one of India's widely used antibiotics, from aqueous solutions using a batch type UV reactor having photon flux = 1.9 (± 0.1) ×10-4 Einstein L-1 min-1. The effects of UV irradiation time on CIP degradation were investigated for both UV and UV-H2O2 processes. It was found that about 75% degradation of CIP was achieved within 60 s with initial CIP concentration and peroxide concentration of 10 mg L-1 and 1 mol H2O2/ mol CIP, respectively, at pH of 7(±0.1) and fluence dose of 113 mJ cm-2. The experimental data were analyzed by the first-order kinetics model to find out the time- and fluence-based degradation rate constants. Under optimized experimental conditions (initial CIP concentration, pH and H2O2 dose of 10 mg L-1, 7(±0.1) and 1.0 mol H2O2 / mol CIP, respectively), the fluence-based pseudo-first-order rate constant for the UV and UV-H2O2 processes were determined to be 1.28(±0.0) ×10-4 and 1.20(±0.04) ×10-2 cm2 mJ-1 respectively. The quantum yields at various pH under direct UV were calculated. The impacts of different process parameters such as H2O2 concentration, solution pH, initial CIP concentration, and wastewater matrix on CIP degradation were also investigated in detail. CIP degradation was favorable in acidic conditions. Six degradation products of CIP were identified. Results clearly showed the potentiality of the UV-H2O2 process for the degradation of antibiotics in wastewater.

Decolorization of Methyl Orange Simulated Wastewater by Chlorine Dioxide with Ultrasound

2011 ◽  
Vol 255-260 ◽  
pp. 2904-2908
Author(s):  
Li Jie Huang ◽  
Ting Xu ◽  
Shuang Fei Wang
Keyword(s):  
Methyl Orange ◽  
Rate Constant ◽  
Chlorine Dioxide ◽  
Oxidation Process ◽  
Order Rate Constant ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Effective Technology ◽  
Simulated Wastewater ◽  
Pseudo First Order

Experiments were conducted to investigate the decolorization of methyl orange simulated wastewater in order to assess the effectiveness and feasibility of ultrasound(US) enhanced high-purity chlorine dioxide(ClO2) oxidation process. The results showed that in ClO2/US system the decolorization rate of methyl orange was up to 96%, which was increased by 8% as compared to ClO2treatment alone. The decolorization of methyl orange with/without ultrasonic irradiation follows apparent pseudo-first-order reaction kinetics. The apparent pseudo-first-order rate constant kappwas 0.19min-1in the ClO2/US system, which was a little higher than 0.13min-1of rate constant achieved in ClO2treatment alone. It shows that ClO2/US system can be an effective technology for the decolorization of azo dyes in wastewater.

Kinetic Study of Degradation of Basic Turquise Blue X-GB and Basic Blue X-GRRL using Advanced Oxidation Process

2020 ◽  
Vol 234 (11-12) ◽  
pp. 1803-1817 ◽  
Author(s):  
Naeem-Ul-Haq Khan ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal ◽  
Arif Nazir ◽  
Hiratul Ain
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Correlation Coefficients ◽  
Advanced Oxidation ◽  
Optimum Conditions ◽  
Oxidation Treatment ◽  
First Order ◽  
Fenton Oxidation Process ◽  
Maximum Decolorization

AbstractThis study focuses on application of advanced oxidation (Photo-Fenton) processes to decolorize Basic Turquise Blue (BTB) X-GB 250% and Basic Blue (BB) X-GRRL 250% dyes. The percent decolorization was studied in terms of effect of variation in intensity of UV light at optimum conditions of all the parameters (pH = 3.0, H2O2 = 4.8 mM, FeSO4 = 1.6 mM, temperature = 50 °C, time = 80 min for BTB X-GB, and pH = 5.0, H2O2 = 5.6 mM, FeSO4 = 2.0 mM, temperature = 40 °C, time = 60 min for BB X-GRRL). Maximum decolorization was obtained at maximum intensity (15660 counts/min) of UV light as 96.17% for BTB X-GB and 88.48% for BB X-GRRL. First order, 2nd order and BMG kinetic models were used to analyze the data obtained for intensity of UV light. BMG model gives us the higher values of correlation coefficients for all data of both the dyes. The results have shown that Photo-Fenton oxidation process is the beneficial and effective for oxidation treatment of waste water effluents containing dyes as main pollutants.

scholarly journals Catalytically Active Gold Nanoparticles Synthesized using Diabetic Sugar Via Rapid, Simple, Greener Process

2019 ◽  
Vol 35 (5) ◽  
pp. 1519-1528
Author(s):  
Nurdiani Nurdiani ◽  
Foliatini Foliatini
Keyword(s):  
Reaction Rate ◽  
Au Nanoparticles ◽  
Colloidal Solution ◽  
Oxidation Process ◽  
Infrared Spectrophotometry ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Catalytically Active ◽  
Kinetics Of ◽  
Hydrolysis Of

Au nanoparticles were successfully synthesized using diabetic sugar as reducing agent, with and without the aid of microwave heating. The hydrolysis of diabetic sugar was carried out using HCl, prior to the synthesis. By adjusting pH of the mixture to basic condition, the formation of the nanoparticles effectively occurred resulting purple colloidal solution. The solution was centrifuged or left overnight to yield precipitate of Au nanoparticles. The as-formed Au nanoparticles were characterized by UV-Vis spectrophotometry, Fourier-Transform infrared spectrophotometry and scanning electron microscopy. The result showed that the Au nanoparticles played a significant role as catalyst for oxidation of methylene blue by H2O2. The kinetics of the oxidation process followed pseudo first order reaction rate with the rate constant depending on the AuNP characteristic and experimental condition.

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

scholarly journals Oxidative degradation of gentamicin present in water by an electro-Fenton process and biodegradability improvement

2019 ◽  
Vol 17 (1) ◽  
pp. 1017-1025
Author(s):  
Mohamed Réda Arhoutane ◽  
Muna Shueai Yahya ◽  
Miloud El Karbane ◽  
Kacem El Kacemi
Keyword(s):  
Chemical Oxygen Demand ◽  
Biological Process ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Polluted Water ◽  
Applied Current ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Appropriate Treatment ◽  
By Products

AbstractIn the context of environmental protection, where there is a need to develop effective operations for carrying out appropriate treatment of polluted water by pharmaceuticals. Therefore, the present study aims at evaluating the degradation for gentamicin through electro-Fenton (EF) operation, through taking into consideration the effect of several parameters of experimental in the process, namely, the concentration of initial gentamicin, the applied current and the Fe+2 (II) quantities. The (EF) operation employed involves a carbon-felt as cathode and platinum as anode at pH 3. Studies for the gentamicin kinetics is monitored by HPLC giving a pseudo-first order reaction following by a chemical oxygen demand, with a reached degree of mineralization 96% after of four hours of treatment through current 100 mA/cm2 with 0.1 mM of Fe+2. We find that the degradation for molecule of gentamicin is accompanied by an augmentation of the biodegradability, assesse through the Biochemical Oxygen Demand (BOD5) on chemical oxygen demand (COD) ratio, that augmentation from 0 to 0.41 before treatment after 30 min for EF treatment, showing that there is potential for conjugation of the EF process and the biological process. Furthermore, the by-products have been identified on the basis of HPLC-MS/MS results.

scholarly journals Dynamics of Oxidation of Reduced Forms of CO2 under Electrochemical and Open-Сircuit Conditions on Polycrystalline Pt in H2CO3

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 274
Author(s):  
Alexander V. Smolin ◽  
Мikhail N. Mikhailov ◽  
Aleksey F. Gadzaov ◽  
Leonid M. Kustov
Keyword(s):  
Quantum Chemical ◽  
Preliminary Analysis ◽  
Oxidation Reaction ◽  
Density Functional ◽  
Oxidation Process ◽  
Open Circuit ◽  
Organic Substances ◽  
Oxidation Of Co ◽  
Reduced Forms

The problem of identifying correlations between catalytic and electrocatalytic processes is one of the fundamental problems of catalysis among “simple” organic substances, and the oxidation of CO and rCO2 is of great interest, since CO and CO2 are considered in pairs both during catalytic and electrocatalytic transformations. In the case of electrocatalysis, this analysis is important in the study of fuel cells. In this paper, we studied the correlation between the oxidation of reduced forms of CO2 (rCO2) under potentiodynamic-galvanoctatic electrochemical and open-circuit conditions of measurements on polycrystalline (pc)Pt in H2CO3. Periodic oscillations are revealed at the oxidation of Had and rCO2 on (pc)Pt. Quantum chemical calculations were carried out on the Pt13 cluster in order to identify the mechanisms of the rCO2 oxidation reaction. The correspondence in the energy parameters of the oxidation process of rCO2 under open-circuit conditions and electrochemical conditions is shown. The preliminary analysis of the system using density functional (DFT) calculations is carried out and the most stable systems that are based on Pt13 are found, namely rOH-Pt13-(CO)n, rOH-Pt13-(COH) and rOH-Pt13-(rCOOH). OH• species was chosen as the most likely candidate for the role of the oxidant for rCO2. Preliminary calculations for the expected reactions were carried out, and the optimal PES is revealed.

The effect of the textile industry dye bath additive EDTMPA on colour removal characteristics by ozone oxidation

2007 ◽  
Vol 55 (10) ◽  
pp. 145-153 ◽  
Author(s):  
T. Ölmez ◽  
I. Kabdaşlı ◽  
O. Tünay
Keyword(s):  
Organic Matter ◽  
Textile Industry ◽  
Reaction Rates ◽  
Textile Dye ◽  
Pseudo First Order Reaction ◽  
Ozone Oxidation ◽  
Reactive Dyeing ◽  
First Order ◽  
Organic Matter Oxidation ◽  
Pseudo First Order

In this study, the effects of the phosphonic acid based sequestering agent EDTMPA used in the textile dye baths on colour and organic matter removal by ozone oxidation was experimentally investigated. Procion Navy HEXL dyestuff that has been commonly used for the reactive dyeing of cellulose fibers was selected as the model component. The organic matter oxidation by ozone was determined to obey the pseudo-first order kinetics as they are treated singly or in combination. COD removal rates obtained from pseudo-first order reaction kinetics showed that oxidation of Navy HEXL alone (0.0947 L/min) was faster than that of EDTMPA (0.0171 L/min) and EDTMPA with dye (0.0155 L/min) at pH 3.0. It was also found that reaction rates of single EDTMPA removal and EDTMPA and dye mixture removal increased as the reaction pH was increased from 3.0 to 10.5.

Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers

2009 ◽  
Vol 59 (7) ◽  
pp. 1361-1369 ◽  
Author(s):  
Edison Gil Pavas ◽  
Miguel Ángel Gómez-García
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Experimental Design ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Effluent Standards ◽  
Degradation Of Dyes ◽  
Pseudo First Order ◽  
Dyes Mixture

This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellín (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO2) and hydrogen peroxide (H2O2). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes.

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