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

Author(s):  
Zahia Benredjem ◽  
Karima Barbari ◽  
Imene Chaabna ◽  
Samia Saaidia ◽  
Abdelhak Djemel ◽  
...  

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.

2011 ◽  
Vol 11 (1) ◽  
pp. 129-134 ◽  
Author(s):  
A. Dulov ◽  
N. Dulova ◽  
Y. Veressinina ◽  
M. Trapido

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.


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

2019 ◽  
Vol 17 (2) ◽  
pp. 254-265 ◽  
Author(s):  
A. Derbalah ◽  
M. Sunday ◽  
R. Chidya ◽  
W. Jadoon ◽  
H. Sakugawa

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.


2018 ◽  
Vol 7 (1) ◽  
pp. 61-67
Author(s):  
Do Ngoc Khue ◽  
Tran Dai Lam ◽  
Dao Duy Hung ◽  
Vu Quang Bach ◽  
Nguyen Van Anh ◽  
...  

AbstractSeveral advanced oxidation processes have been performed for the decomposition of ester nitrates (ENs), such as nitroglycerine (NG) and pentaerythritol tetranitrate (PETN). The reaction kinetics for removing NG and PETN by some of the advanced oxidation processes (e.g. UV-H2O2, Fenton, UV-Fenton) followed the pseudo-first-order model. The reaction rates in different systems followed the sequence ENs/UV<ENs/H2O2<ENs/UV-H2O2<ENs/Fenton<ENs/UV-Fenton. The effect of various parameters, such as pH, concentration of hydrogen peroxide, and temperature, on the degradation of NG and PETN were studied.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1813
Author(s):  
Aneta Sokol ◽  
Artur Ratkiewicz ◽  
Iwona Tomaszewska ◽  
Joanna Karpinska

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.


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 ◽  
...  

2018 ◽  
Vol 54 (82) ◽  
pp. 11622-11625 ◽  
Author(s):  
Xiaomei Cheng ◽  
Lianhai Zu ◽  
Yue Jiang ◽  
Donglu Shi ◽  
Xiaoming Cai ◽  
...  

A pseudo-Fenton reaction works synergistically with photocatalysis to greatly accelerate the oxidative degradation rate.


2007 ◽  
Vol 4 (5) ◽  
pp. 355 ◽  
Author(s):  
Józef Ziajka ◽  
Krzysztof J. Rudzinski

Environmental context. Chlorophenols pollute natural waters and soils, as well as urban waste water systems. Although toxic and carcinogenic to animals and humans, a detailed knowledge of their action is limited. A new approach to effective degradation in the environment is advanced oxidation processes with sulfate radicals. The radicals can originate from the oxidation of sulfur dioxide or sulfites to make these common pollutants and food additives interact with chlorophenols. The main goal of this work is to determine rate constants for reactions of these chlorophenols with sulfate radicals in order to shed some light on the chemical kinetics of these reactions. Abstract. Kinetic experiments have shown that six chlorophenols (CPs) inhibit the autoxidation of SIV catalysed by Fe(ClO4)3 in aqueous solution at 25°C and pH ≈ 3.0. Efficiency of the inhibition decreases with the number of chlorine substituents for all CPs except for 2,5-dichlorophenol (2,5-DCP), which ranked between the tri- and tetrachlorophenols. The inhibition is explained by reactions of chlorophenols with sulfate radicals, the chain carriers in the mechanism of autoxidation. Rate constants for these reactions are determined for the first time, using the reversed-rates method with ethanol as a reference inhibitor: 8.7 × 109 (4-CP), 7.4 × 109 (2,4-DCP), 1.9 × 109 (2,5-DCP), 2.4 × 109 (2,4,5-TCP), 2.9 × 109 (2,4,6-TCP), and 7.5 × 108 (2,3,5,6-TTCP); 4.3 × 107 (ethanol reference) M–1 s–1. Linear correlations were derived for the estimation of rate constants for the remaining chlorophenols using sums of Brown substituent coefficients or relative strengths of O–H bonds. The results can be used in the development of advanced oxidation processes that utilise sulfate radicals for mineralisation of chlorophenols in wastewaters, and also demonstrate that chlorophenols can extend the lifetimes of SO2 and sulfites in natural and atmospheric waters.


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