Photocatalysed Oxidation of Toxic Organics

1987 ◽  
Vol 19 (3-4) ◽  
pp. 381-390 ◽  
Author(s):  
M. Brett Borup ◽  
E. Joe Middlebrooks
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Radiation ◽  
Organic Compounds ◽  
Hydroxyl Radicals ◽  
Reaction Rate ◽  
Oxidation Process ◽  
Dimethyl Phthalate ◽  
First Order ◽  
Toxic Organics ◽  
Catalyzed Oxidation

The feasibility of treating water contaminated by two toxic organic compounds with an ultraviolet light catalyzed oxidation process using hydrogen peroxide as an oxidant is investigated. In this process hydrogen peroxide is decomposed by ultraviolet radiation producing hydroxyl radicals. The hydroxyl radicals will then oxidize organic compounds via a complex chain of radical reactions. Tests showed that this photooxidation process could successfully remove isophorone and dimethyl phthalate from contaminated waters. A reaction rate expression which adequately describes the process was developed. The reaction rate was found to be first order with respect to hydrogen peroxide concentration, zero order with respect to organic concentration and a function of ultraviolet radiation intensity. The reaction did not exhibit autocatalytic characteristics.

scholarly journals KINETIKA PROSES AOPs UNTUK PENGHILANGAN WARNA AIR LIMBAH PRODUKSI BATIK

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Rudi Nugroho ◽  
Ikbal Mahmud
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Compounds ◽  
Azo Dyes ◽  
Reaction Rate ◽  
Pilot Scale ◽  
Colour Removal ◽  
First Order ◽  
Order Chemical Reaction ◽  
First Order Chemical Reaction ◽  
Long Chain

An experiment of Advanced Oxydation Processes (AOPs) was conducted in semi-pilot scale using ozon and hydrogen peroxide. The reaction of ozon and hydrogen peroxide  produce an active hydroxil which can crack a long-chain organic compounds such as azo dyes. A wastewater contains colour substances coming from batik industries in Jababeka was treated by AOPs. The reaction rate was affected by ozon concentration supplied to the wastewater. The more ozon concentration, the colour removal became faster.The colour removal using AOPs could be illustrated by first-order chemical reaction equation.The constant of reaction was calculated from experiment as high as 0,38 per hour.The cost for treating the wastewater using AOPs was  Rp.3.656,- for one cubic meter of wastewater. Key words:  AOPs, Colour Removal, Hydrogen Peroxide, Ozon,

scholarly journals Ruthenium(III) Catalysis in Perborate Oxidation of 5-Oxoacids

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
S. Shree Devi ◽  
P. Krishnamoorthy ◽  
B. Muthukumaran
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Acidic Solution ◽  
Activation Parameters ◽  
Reactive Species ◽  
Rate Law ◽  
First Order ◽  
Catalyzed Oxidation ◽  
Electron Withdrawing Substituents

Ruthenium(III) catalyzes perborate oxidation of substituted 5-oxoacids in acidic solution. The catalyzed oxidation is first order with respect to the oxidant and catalyst. The rate of ruthenium(III) catalyzed oxidation displays the Michaelis-Menten kinetics on the reductant and is independent of [H+] of the medium. Hydrogen peroxide is the reactive species of perborate and the kinetic results reveal formation of ruthenium(III) peroxo species-5-oxoacid complex. Electron-releasing substituents accelerate the reaction rate and electron-withdrawing substituents retard it. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫  p-methyl > p-phenyl > −H > p-chloro > p-bromo > m-nitro. Activation parameters are evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data is proposed and discussed. A suitable rate law is derived based on the mechanism.

scholarly journals Kinetics and Mechanistic Study of Cetyltrimethylammonium Bromide Catalyzed Oxidation of Tetraethylene Glycol byN-Chlorosaccharin in Acidic Medium

2008 ◽  
Vol 5 (3) ◽  
pp. 598-606
Author(s):  
Vandana Sharma ◽  
K. V. Sharma ◽  
V. W. Bhagwat
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Mechanistic Study ◽  
Tetraethylene Glycol ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
First Order ◽  
Dielectric Effect ◽  
Catalyzed Oxidation

The kinetics and mechanism of cetyltrimethylammonium bromide catalyzed oxidation of tetraethylene glycol [2,2'-(oxibis(ethylenoxy)diethanol)] byN-chlorosaccharin in aqueous acetic acid medium in presence of perchloric acid have been investigated at 323K. The reaction is first order dependence on Nchlorosaccharin. The reaction rate follows first order kinetics with respect to [tetraethylene glycol] with excess concentration of other reactants. The miceller effect due to cetyltrimethylammonium bromide, a cationic surfactant has been studied. The change in ionic strength shows negligible salt effect. The dielectric effect is found to be positive. Addition of one of the products (saccharin) retards the reaction rate. Activation parameters are calculated from the Arrhenious plot. A possible mechanism consistent with the experimental results has been proposed.

Destruction of Pollutants and Microorganisms in Water by UV Light and Hydrogen Peroxide

1992 ◽  
Vol 27 (1) ◽  
pp. 57-68 ◽  
Author(s):  
D.W. Sundstrom ◽  
B.A. Weir ◽  
T. A. Barber ◽  
H. E. Klei
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Compounds ◽  
Chemical Structure ◽  
Uv Light ◽  
Liquid Films ◽  
Strong Interactions ◽  
Order Kinetic ◽  
E Coli ◽  
Order Kinetic Model ◽  
Catalyzed Oxidation

Abstract This project investigated the destruction of organic compounds and microorganisms in water by ultraviolet catalyzed oxidation using hydrogen peroxide as the oxidizing agent. The combination of UV light and hydrogen peroxide was effective in decomposing all of the organic compounds studied. The rates of destruction increased with increasing peroxide concentration and UV light intensity, and were highly dependent on chemical structure. The destruction of mixtures of organic compounds showed strong interactions between reacting components. The inactivation of E. coli and B. subtilis spores by UV light and/or hydrogen peroxide was studied in flat plate reactors. By using thin liquid films, the combination of UV light and peroxide greatly increased the rates of inactivation of both microorganisms. The results were correlated by a mixed second order kinetic model.

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.

Hydrogen Peroxide Decay in Waters with Suspended Soils: Evidence for Biologically Mediated Processes

1990 ◽  
Vol 47 (5) ◽  
pp. 888-893 ◽  
Author(s):  
William J. Cooper ◽  
Richard G. Zepp
Keyword(s):  
Hydrogen Peroxide ◽  
Natural Water ◽  
Water Samples ◽  
First Order ◽  
Natural Water Samples ◽  
Major Reaction Product ◽  
Major Reaction ◽  
Chemical Sterilization ◽  
Pseudo First Order ◽  
Catalyzed Oxidation

Hydrogen peroxide decay studies have been conducted in suspensions of several well-characterized soils and in natural water samples. Kinetic and product studies indicated that the decay was biologically-mediated, and could be described by pseudo first-order rate expressions. At an initial H2O2 concentration of 0.5 μM, the hydrogen peroxide half-life varied from 1 to 8 h. The decay was inhibited by thermal and chemical sterilization of the soils. Peroxidase activity was inferred in several natural water samples, where the suspended particles catalyzed the oxidation of p-anisidine by hydrogen peroxide. The mass spectrum of the major reaction product indicated that it was the dimer, possibly benzoquinone-4-methoxyanil, a product that also was observed from the horseradish peroxidase-catalyzed oxidation of p-anisidine by hydrogen peroxide.

Reuse of Homogeneous Fenton’s Sludge from Detergent Industry as Fenton’s Catalyst

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
André F. Rossi ◽  
Rui C. Martins ◽  
Rosa M. Quinta-Ferreira
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Heterogeneous Catalysts ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Iron Catalyst ◽  
Advanced Oxidation ◽  
Detergent Industry ◽  
Oxidizing Agent ◽  
Fenton’S Reaction

AbstractFenton’s reaction is an advanced oxidation process where, classically, hydrogen peroxide is the oxidizing agent and an iron catalyst promotes the formation of hydroxyl radicals (•OH). Among the studies that evaluated different metals as Fenton-like catalysts, our group of investigation has recently used cerium-based solids as heterogeneous catalysts in slurry reaction and, in this work, iron sludge coming from an industrial Fenton’s reactor used for the wastewater depuration of a detergent production factory is being appraised while treating a synthetic effluent containing 0.1 g.L

Kinetics and Mechanism of Oxidation of Selenium(IV) by Permanganate Ion in Aqueous Perchlorate Solutions

1993 ◽  
Vol 58 (3) ◽  
pp. 538-546 ◽  
Author(s):  
Refat M. Hassan ◽  
Sahr A. El-Gaiar ◽  
Abd El-Hady M. El-Summan
Keyword(s):  
Reaction Mechanism ◽  
Reaction Rate ◽  
Oxidation Process ◽  
Selenium Dioxide ◽  
Order Reaction ◽  
Acid Solutions ◽  
First Order ◽  
Acid Catalyzed ◽  
Mechanism Of Oxidation ◽  
Kinetics Of

The kinetics of permanganate oxidation of selenium dioxide in perchloric acid solutions at a constant ionic strength of 2.0 mol dm-3 has been investigated spectrophotometrically. A first-order reaction in [MnO4-] and fractional order with respect to selenium(IV) were observed. The reaction rate was found to be pH-independent at lower acid concentrations ([H+] < 0.5 mol dm-3) and was acid-catalyzed beyond this range. Addition of Mn2+ and F- ions leads to the prediction that MnO4- is the sole reactive species in the oxidation process. A tentative reaction mechanism consistent with the reaction kinetics has been proposed.

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