Oxidative Degradation Of Methyl Orange Research Articles

ПРОЦЕС “СОНОПЕРОКСАТ” ДЛЯ ОКИСНЮВАЛЬНОЇ ДЕГРАДАЦІЇ МЕТИЛОВОГО ОРАНЖЕВОГО

The efficiency of application of advanced oxidation processes for removal of methyl orange mono azo dye from wastewater is considered. For intensive oxidative degradation of methyl orange, it was proposed to use a combination of ultrasonic cavitation and “Peroxate” process – the “Sonoperoxate” process. Rational conditions for oxidative degradation of methyl orange at its initial concentration in an aqueous solution of 25 mg/dm3 (76.5·10-6 mol/dm3) were established: the molar ratio of methyl orange:hydrogen pero- xide:potassium metaperiodate = 1:50:10; pH of the reaction medium – 3; temperature – 293 K; specific power of cavitation ultrasonic treatment – 68 W/dm3. Under such conditions, the degradation degree of methyl orange of 89.4 % was achieved for 1800 s.

Photocatalytic oxidative degradation of methyl orange by a novel g-C3N4@ZnO based on graphene oxide composites with ternary heterojunction construction

Photocatalytic oxidative degradation of methyl orange by a novel g-C3N4@ZnO based on graphene oxide composites with ternary heterojunction construction

Ce2O3/BiVO4 Embedded in rGO as Photocatalyst for the Degradation of Methyl Orange under Visible Light Irradiation

A p–n heterojunction semiconductor structure composed of Ce3O4 and BiVO4 has been synthesized and then incorporated into reduced graphene oxide (rGO) by the hydrothermal method. The ternary composites were characterized by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), and UV–vis spectroscopy. The efficiency of the composites as photocatalysts was determined by studying the oxidative degradation of methyl orange in aqueous solution under visible light irradiation. The effect of parameters such as pH, catalyst loading, and concentration of the dye solution was examined in order to determine their influence on the photocatalytic activity of the composites. The composite incorporated into reduced graphene oxide presented the highest percentage (above 90%) in 2 h time, attributed to the effect of the increased surface area. The process of the enhanced photocatalytic activity has been discussed based on the energy band positions of the nanoparticles within the composite.

Facile fabrication of PS-CHO@CeO2 core-shell composite microspheres via in-situ chemical deposition and their photocatalytic application on oxidative degradation of MO

In this study, the modified polystyrene aldehyde microspheres (PS-CHO) were first prepared via the copolymerization of the styrene and the acrolein, and then PS-CHO@CeO2 composite microspheres were fabricated through in-situ chemical deposition of CeO2 nanoparticles. These composite microspheres were used to catalyze the oxidative degradation of methyl orange (MO) by H2O2. The morphology of the products was observed by transmission electron microscopy (TEM). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the chemical state and structure. Optical absorption and band energy properties were investigated by ultraviolet-visible/near-infrared diffuse reflectance spectra (UV-Vis-NIR). The degradation process was monitored with ultraviolet-visible spectrometer (UV-Vis). The results revealed that when the mass ratio of PS-CHO and cerium nitrate was 1:0.26, highly-uniformed and well-dispersibility PS-CHO@CeO2 composite microspheres were obtained at pH 8.5 and the concentration of Ce[Formula: see text] ions was significantly increased compared with commercial CeO2 NPs. Under ultraviolet light irradiation, the degradation efficiency of MO by PS-CHO@CeO2 composite microspheres was increased up to 93.03%, which was 1.44 times that of commercial CeO2 NPs in 120 min. The reiteratively tests further proved that the activity of the composite microspheres maintained unchanged after four cycles. The formation and photocatalytic mechanisms of PS-CHO@CeO2 composite microspheres were proposed.

A new two-fold interpenetrating two-dimensional copper(II) coordination polymer constructed from 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether

Abstract A new Cu(II) metal-organic framework, [Cu(BMIOPE)(Br-BDC)] n (1) [Br-H2BDC = 5-bromo-isophthalic acid, BMIOPE = 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether], has been hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis, and single-crystal X-ray diffraction. Complex 1 possesses a unique two-fold interpenetrating two-dimensional framework with sql topology. The photocatalytic property of complex 1 for oxidative degradation of methyl orange and methylene blue with hydrogen peroxide was examined under UV irradiation.

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Low-cost 2D cupric oxide nanoleaves (CuO NLs) are straightforwardly synthesized at room temperature by precipitation varying the addition method of the alkali. No further treatments are necessary t...

Novel synthesis of nanoscale zerovalent iron from coal fly ash and its application in oxidative degradation of methyl orange by Fenton reaction.

We firstly developed a novel synthesis method of nanoscale zerovalent iron (NZVI) using Fe sources in coal fly ash (CFA) for the oxidative degradation of methyl orange by Fenton reaction. Hydrochloric acid (HCl) and methyl isobutyl ketone (MIBK) were used for Fe dissolution from CFA and selective Fe(III) chelation, respectively. Among varied HCl concentrations, 7 N HCl showed the best performance for the oxidation of aqueous Fe(II) to Fe(III) and efficient chelation of Fe(III) with MIBK. The NZVI-CFA was synthesized by adding NaBH4 to a solution of Fe(III)-chelated MIBK, yielding NZVI transformation >95% from Fe(III) in HCl. Various surface analyses were performed to characterize the NZVI-CFA, which was almost identical to typical NZVI-Bare. HCl and MIBK could be reused several times, indicating potential reusability of chemicals used in the synthesis. Remarkable >96% decolorization of methyl orange was obtained by the NZVI-CFA-induced Fenton reaction at pH 3, with a ∼22% decrease in total organic carbon in 7 min. The heterogeneous Fenton reaction initiated by NZVI-CFA with H2O2 showed reactivity similar to that of the homogeneous Fenton reaction (i.e., aqueous Fe(II) with H2O2), indicating the importance of homogeneous reaction for the oxidative degradation of methyl orange.

Oxidative Degradation of Methyl Orange Solution by Fe-MKSF Catalyst: Identification of Radical Species

Iron–immobilized montmorillonite KSF (Fe-MKSF) has been recognized as promising catalyst in degrading persistence organic contaminants. However, detailed mechanistic insight during the catalysis which involving the formation and identification of radical species were remained indeterminate due to complex reaction. Inspiring by this gap, iron-immobilized clay (Fe-MKSF) was synthesized and used as heterogeneous catalyst in the oxidative degradation of methyl orange (MO) solution. Identification of radical species were determined through the inclusion of different types of radical scavenging agent during the Fenton-like reaction at optimum condition. Interestingly, dominant radical species were found to be hydroperoxyl radicals (•OOH) which subsequently followed by hydroxyl radicals (•OH) during the catalysis. Based on the percentage of MO removal, it was suggested that approximately 88% of the •OOH radicals existed at the interface of catalyst while 39% presence in bulk solution. Meanwhile, the interface •OH radicals promoted 38% of MO removal, whilst 4% by the bulk •OH radicals. Hence, these findings have conveyed novel insight on detailed radicals’ identification as well as its’ interaction during the catalysis.

Fe-MKSF catalyst for oxidative degradation of methyl orange: influence of iron/clay ratio

Heterogeneous Fenton-like reaction has received considerable research attention as one of promising treatment methods in degrading recalcitrant organic pollutant. In recent years, iron immobilized-montmorillonite KSF (Fe-MKSF) catalyst displayed decent catalytic activity in degrading organic contaminants. Inspired by such performances, further understanding on the detailed structural properties as well as its’ catalytic activity were performed to gain further insights towards the influence of iron to clay ratio during the catalyst synthesis. Fe-MKSF catalysts were synthesized by impregnation-hydrothermal method at varies iron molarity to the clay ratio. A series of Fe-MKSF catalyst ranging between 10 until 50 molarity of iron/clay ratio as well as pristine MKSF and iron oxide were characterized using nitrogen sorption and XRD analysis. The catalytic performance of resultantFe-MKSF catalysts were tested for the oxidative degradation of methyl orange (MO) in heterogeneous Fenton-like reaction. At pH 3, 0.2 g/L Fe-MKSF, 12 mM of hydrogen peroxide and 25 mg/L MO’s initial concentration; Fe-MKSF-20 exhibited with exceptional performance of 85% removal. Such behavior was attributed to the high surface area (SBET=105.76 m2/g) and pore volume (0.39 cm3/g) of Fe-MKSF-20 compared with others iron/clay ratio. Moreover, form the XRD analysis, it was found that the immobilized iron on the MKSF was in hematite phase for all Fe-MKSF catalysts. In conclusion, the iron/clay ratio plays vital role in modulating the structural properties, which directly corresponded to the resultant catalytic activity of Fe-MKSF

Optimization of oxidative MO’s degradation in heterogeneous Fenton-like reaction using Fe-MKSF

This study investigates the optimal operational conditions for oxidative degradation of methyl orange (MO) in heterogeneous Fenton-like reaction using iron-immobilized montmorillonite KSF (Fe-MKSF) composites. Central composite design (CCD) experiments were used to determine the effects of four operational variables; pH solution, catalyst dosage, concentration of H2O2 and initial concentration of methyl orange dye (MO) on the percentage of MO removal. Based on the analysis of variance (ANOVA), the model illustrated high correlation coefficient (R2) of 0.9589 which demonstrated approximately 96% of target function variation. The optimal operational conditions were found to be at 2.8 pH solution, 0.8g/L catalyst dosage, 15 mM H2O2 concentration and 25 mg/L MO initial concentration which subsequently resulted in 98% of MO removal. Moreover, the experimental values obtained were in good agreement with the values predicted from the model, with relatively slight differences of 1.24%. Such findings shown significant interaction between four operational variables towards MO removal during the heterogeneous Fenton-like reaction using Fe-MKSF composites.

Photo Degradation of Methyl Orange by Persulfate Activated with Zero Valent Iron

The oxidative degradation of Methyl Orange (MO) subjected to direct photolysis (Solar) and various oxidative systems was studied. The comparative experiments have shown that MO conversion and mineralization increases in the following order: Solar ∼ Solar/Fe0 ∼ Solar/S2O82- < S2O82-/Fe0 < Solar/S2O82-/Fe0. The influence of the main factors (duration of exposure, the ratio of initial concentrations of MO:S2O82-:Fe0, pH and temperature of the reaction medium) on the degree of MO conversion and mineralization was studied. The optimal pH and temperature of the reaction medium were 5.8 and 25°C, respectively. The rate of MO decomposition and mineralization increased proportionally to the initial concentration of the oxidant at the molar ratios [S2O82-] :[MO] ≤ 12. Judging by the nature of the kinetic curves, a further increase of this ratio is impractical. However, an increase in the oxidant concentration had a positive effect on the degrees of conversion and mineralization of total organic carbon (TOC). Thus, at the ratios of 12:1 and 48:1, the conversion efficiency of TOC was 23 and 60 %, respectively. The optimal concentration of Fe0 was 100 mg/l.

Metal-based mesoporous materials and their application as catalysts for the degradation of methyl orange azo dye

Cobalt, manganese and copper heterogeneous catalysts were prepared using MCM-41 and SBA-16 mesoporous supports. The synthesized materials were characterized by X-ray diffraction, chemical analysis, N2 sorptometry, vibrational spectroscopy and transmission electron microscopy. Their catalytic activity was studied in the oxidative degradation of methyl orange (MO) in aqueous solution, at pH 6, using persulfate (PS) anion as oxidant at 30°C. The level of degradation of the dye was monitored by UV–vis spectroscopy and Total Organic Carbon (TOC) analysis. The synthesized materials showed high activity, being the most effective catalysts those based on Co and Cu, achieving an efficient dye decolorization of >95% until 2h of reaction. After 24h of reaction a high degree of mineralization was achieved (>70%). Radical quenching studies showed that sulfate radicals are the main species formed by the catalyst/PS interaction. The supported catalysts exhibited stable performance during the reusability test, reaching an activity greater than 90% up to the fifth evaluated cycle of reuse for copper and cobalt based catalysts.

Enhancement of Fe3O4/Au Composite Nanoparticles Catalyst in Oxidative Degradation of Methyl Orange Based on Synergistic Effect

Enhancement of Fe3O4/Au nanoparticles (Fe3O4/Au NPs) catalyst was observed in the oxidative degradation of methyl orange by employing H2O2 as oxidant. To evaluate the catalytic activity of Fe3O4/Au nanoparticles, different degradation conditions were investigated such as the amounts of catalyst, H2O2 concentration and pH value. Based on our data, methyl orange was degraded completely in a short time. The enhanced catalytic activity and increased oxidation rate constant may be ascribed to synergistic catalyst‐activated decomposition of H2O2 to •OH radical, which was one of the strong oxidizing species. Besides, Fe3O4/Au nanoparticles have exhibited satisfying recycle performance for potential industrial application.

Silica-Supported Co3O4 Nanoparticles as a Recyclable Catalyst for Rapid Degradation of Azodye

In this paper, silica nanoparticles with particle size of ~ 10-20 nm were selected as a support for the synthesis of Co3O4 nanoparticles by impregnation of silica nanoparticles in solution of Co(II) in a specific concentrations and then calcination to 800 oC. This nanocomposite was then, used as a catalyst for oxidative degradation of methyl orange (MO) with ammonium persulfate in aqueous media. Effect of pH, temperature, contact time, amount of oxidant and catalyst were studied in the presence of manuscript. Scanning electron microscope (SEM), electron dispersive spectroscopy (EDS), FT-IR, and ICP-AES analyses were used for analysis of silica-supported Co3O4 (Co3O4/SiO2). Treating MO with ammonium persulfate in the presence of Co3O4/SiO2 led to complete degradation of MO under the optimized conditions. Also, the catalyst exhibited recyclability at least over 10 consecutive runs.

Enhanced catalytic performance of β-FeOOH by coupling with single-walled carbon nanotubes in a visible-light-Fenton-like process

Abstract Carbon nanotubes/akaganeite composite photocatalysts (CNTs/β-FeOOH) with different weight addition ratios of CNTs have been synthesized by a very simple hydrothermal method. X-ray diffraction, Fourier transform infrared spectrum, UV-vis diffuse reflectance spectra, scanning electron microscopy, and transmission electron microscope were used to characterize the composite photocatalysts. This study investigates the oxidative degradation of methyl orange, a probe contaminant, by a heterogeneous photo-Fenton-like process over the prepared composite photocatalysts. The CNTs/β-FeOOH composites exhibit remarkably enhanced photocatalytic activity toward the degradation of methyl orange in water under visible light irradiation as compared with bare β-FeOOH. The added CNTs have triple crucial roles in the promotion of photocatalytic activity of β-FeOOH. One is to trap electrons and effectively hinder recombination of the photoexcited carriers. Two is to act as a dispersing support to control the particle size of β-FeOOH in the CNTs/β-FeOOH composites. Three is to enhance the visible light absorption intensity. Finally, the catalytic mechanism of CNTs/β-FeOOH composite is proposed.

Repeated oxidative degradation of methyl orange through bio-electro-Fenton in bioelectrochemical system (BES)

Composite Fe2O3/ACF electrode facilitated methyl orange (MO) oxidative degradation using bio-electro-Fenton in bioelectrochemical system (BES) was investigated. Characterized by both XPS and FT-IR techniques, it was found that the composite Fe2O3/ACF electrode with highest Fe loading capacity of 11.02% could be prepared after the carbon felt was oxidized with nitric acid. Moreover, hydrogen peroxide production reached steadily at 88.63μmol/L with the external resistance as 100Ω, cathodic aeration rate at 750mL/min, and the pH of the bio-electro-Fenton system adjusted to 2. Significantly, not only the electrochemical profiles of the BES reactor as electrochemical impedance spectroscopy (EIS) was bettered, but the MO oxidative degradation could be accomplished for eight repeated batches, with the MO removal efficiency varied slightly from 73.9% to 86.7%. It indicated that the bio-electro-Fenton might be a promising eco-friendly AOP method for Azo-dye wastewater treatment.

Efficient removal of dye from an aqueous phase using activated carbon supported ferrihydrite as heterogeneous Fenton-like catalyst under assistance of microwave irradiation

Ferrihydrite (Fh) stabilized inside porous activated carbon (Fh/AC) was prepared and used as a heterogeneous Fenton-like catalyst for oxidative degradation of methyl orange (MO) in simulated dye wastewater. The prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and N2 adsorption–desorption isotherm. It was found that ferrihydrite was highly dispersed on the surface of pretreated AC and the as-prepared Fh/AC exhibited catalytic activity for degradation of MO in the Fenton-like system consisting of solid catalyst, hydrogen peroxide (H2O2) and MO solution. With the assistance of microwave (MW) irradiation, the degradation efficiency of MO was significantly enhanced, indicating a synergetic effect of MW and Fenton-like system. The initial pH value of MO solution exerted notable influence on the reaction and acidic condition is more favorable to the degradation of MO. The recyclability of the catalyst was also evaluated by successive batch experiments under optimum conditions.

Microwave Catalyzed Oxidative Degradation of Methyl Orange in Simulated Wastewater Using Microwave Catalytic TiO2/AC and Mechanistic Studies

Microwave Catalyzed Oxidative Degradation of Methyl Orange in Simulated Wastewater Using Microwave Catalytic TiO2/AC and Mechanistic Studies

Oxidative degradation of Methyl Orange catalyzed by lab prepared nickel hydroxide in aqueous medium

This study is focused on oxidative degradation of Methyl Orange, a common azo dye, catalyzed by nickel hydroxide in aqueous solution at 303, 313, 323, and 333 K. Sodium hypochlorite, sodium hydroxide, and nickel sulfate hexahydrate in distilled water were used as starting material for preparation of nickel hydroxide. Pyrex glass batch reactor was used to study the effect of various conditions such as temperature, concentration, agitation, and catalyst dose on catalytic degradation of Methyl Orange in aqueous medium. About 80% Methyl Orange was degraded in 120 min. Experimental data were subjected to kinetic analysis using CurveExpert software. Degradation reaction was taking place according to Langmuir–Hinshelwood mechanism. According to this mechanism, the reactants adsorb at the surface of catalyst in first step followed by reaction between adsorbed reactants in second step. Adsorption of Methyl Orange on surface of catalyst followed Langmuir adsorption isotherm. Apparent activation energy, true activation energy, and heat of adsorption were determined as 13.2, 32.7 and –23.5 kJ mol−1, respectively.

Catalyzed oxidative degradation of methyl orange over Au catalyst prepared by ionic liquid-polymer modified silica

A new type of hybrid material was prepared by grafting an ionic liquid monomer, 1-(p-vinylbenzyl)-3-methylimidazolium chloride, on the surface of the porous silica which was synthesized via sodium silicate hydrolysis. The as-synthesized products were characterized by scanning electron microscope, nitrogen physisorption experiment, thermogravimetric analysis and Fourier transform infrared spectra. A catalyst with Au was prepared using the hybrid material as carrier. The experimental results show that the catalyst exhibits a better catalytic effect of hydrogen peroxide on the degradation of methyl orange. The reason may be that the metal component of the catalyst facilitated the dissociation of hydrogen peroxide to produce abundant highly active free radicals which can rapidly ruin the structure of methyl orange molecules in water. Finally, a probable catalytic degradation mechanism based on diffusion was discussed.