Photodegradation of aqueous methyl orange on MnTiO3 powder at different initial pH

Oxidative decolorization of azo dyes with a heterogeneous catalyst copper phthalocyanine supported Mg-Al hydrotalcites was studied and the influence factors such as initial pH value, temperature, H2O2 and CuPc-LDHs/H2O2 system were discussed. The results indicated that acidic solution and high temperature were conducive to oxidative decoloration of methyl orange. CuPc-LDHs/H2O2 system showed excellent oxidative decoloration capacity to remove azo dyes. The effects of oxidative decolorization of azo dyes were related to the molecular structure and weight of azo dyes. Oxidative decoloration effects followed the order as congo red > amido black > methyl blue> methyl orange> methylene blue.

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Effective Photodegradation of Methyl Orange Using Fluidized Bed Reactor Loaded with Cross-Linked Chitosan Embedded Nano-CdS Photocatalyst

International Journal of Chemical Engineering ◽

10.1155/2014/270946 ◽

2014 ◽

Vol 2014 ◽

pp. 1-16 ◽

Cited By ~ 7

Author(s):

Wai Szeto ◽

Chi Wai Kan ◽

C. W. M. Yuen ◽

Shun-Wan Chan ◽

Kim Hung Lam

Keyword(s):

Methyl Orange ◽

Dye Removal ◽

Kinetic Constant ◽

Sorption Process ◽

Cross Linking ◽

Solution Ph ◽

Removal Capacity ◽

Transmission Electron ◽

Initial Ph ◽

Visible Reflectance

Chitosan-based photocatalyst composites containing CdS nanocrystals with and without glutaraldehyde or epichlorohydrin cross-linking treatments were investigated and the catalyzed photodegradation of methyl orange in aqueous solution was examined. In addition, the effects of catalyst dosage, initial dye concentration, and initial pH of the dye solution on the photodegradation kinetics were investigated. In this study, the effect of initial solution pH was more important than other factors. The photocatalyst composite could remove 99% dye in 80 minutes at pH 4. The catalyst composite was characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared (FT-IR), and visible reflectance spectroscopy. The dye removal mechanism of methyl orange involved an initial sorption process followed by photodegradation. The sorption process underwent the pseudo-second order kinetics, while photodegradation followed the Langmuir-Hinshelwood kinetics. Although the glutaraldehyde cross-linked chitosan enhanced the initial dye sorption, the epichlorohydrin cross-linked catalyst composite demonstrated a better overall dye removal performance, especially in the photodegradation step. Both chitosan encapsulated catalyst with and without epichlorohydrin cross-linking demonstrated the same pseudo-first order photodegradation kinetic constant of 0.026 min−1and the same dye removal capacity. The catalyst composite could be reused but the photocatalytic activity dropped successively in each cycle.

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Decolorization of methyl orange by green rusts with hydrogen peroxide at neutral pH

Water Science & Technology ◽

10.2166/wst.2013.716 ◽

2013 ◽

Vol 69 (2) ◽

pp. 371-377 ◽

Cited By ~ 6

Author(s):

Yulong Lin ◽

Caiqin Yang ◽

Rong Xiu ◽

Jing Wang ◽

Yu Wei ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Methyl Orange ◽

Xrd Analysis ◽

Oxidation Reactions ◽

X Ray Diffraction ◽

Heterogeneous Fenton ◽

X Ray ◽

Magnetite Fe3o4 ◽

Initial Ph ◽

Green Rusts

Heterogeneous Fenton-like processes using green rusts (GRs) with hydrogen peroxide (H2O2) were studied to decolorize methyl orange (MO) in aqueous solution at an initial pH of 7.0. In this study, two types of crystal structure for GRs, the hydroxycarbonate GR(CO32–) (GR1) and the hydroxysulphate GR(SO42–) (GR2), were synthesized by partial oxidation of Fe(OH)2 suspension under light irradiation and distinguished by X-ray diffraction (XRD) due to different characteristic peaks. In oxidation reactions, decolorization rate of MO, bubbling air through the solution, was about 65% (experiment B), whereas, it was up to 95% in the presence of H2O2 (experiment C) within 60 min. The comparative tests of GR1 and GR2 show that the reduction capability of GR2 is stronger than GR1, which may be due to Fe(II) content and interlayer anions. XRD analysis and Fourier transform infrared spectroscopy revealed that the oxidation end products of GR2 were mainly a poorly crystallized mixture of magnetite (Fe3O4) and hydroxy ferric oxide (FeOOH). However, when GR was immediately oxidized, the weakly crystallized goethite (α–FeOOH) and lepidocrocite (γ–FeOOH) were formed for O2 and H2O2, respectively. Based on the intermediates obtained, a probable decolorization mechanism has been proposed.

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Photodegradation of methyl orange aqueous on MnWO4 powder under different light resources and initial pH

Desalination ◽

10.1016/j.desal.2009.10.024 ◽

2010 ◽

Vol 252 (1-3) ◽

pp. 66-70 ◽

Cited By ~ 67

Author(s):

H.Y. He ◽

J.F. Huang ◽

L.Y. Cao ◽

J.P. Wu

Keyword(s):

Methyl Orange ◽

Initial Ph

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Photocatalytic Degradation of Methyl Orange on Bi2O3 and Ag2O-Bi2O3 Nano Photocatalysts

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.12.1.623.96-105 ◽

2017 ◽

Vol 12 (1) ◽

pp. 96 ◽

Cited By ~ 1

Author(s):

Seyed Ali Hosseini ◽

Ramin Saeedi

Keyword(s):

Methyl Orange ◽

Visible Light ◽

Photocatalytic Degradation ◽

Average Crystallite Size ◽

Chemical Precipitation ◽

Sem Analysis ◽

Precipitation Method ◽

Degradation Of Dyes ◽

Initial Ph ◽

Degradation Of Methyl Orange

The photocatalytic activity of Bi2O3 and Ag2O-Bi2O3 was evaluated by degradation of aqueous methyl orange as a model dye effluent. Bi2O3 was synthesized using chemical precipitation method. Structural analysis revealed that Bi2O3 contain a unique well-crystallized phase and the average crystallite size of 22.4 nm. The SEM analysis showed that the size of Bi2O3 particles was mainly in the range of 16-22 nm. The most important variables affecting the photocatalytic degradation of dyes, namely reaction time, initial pH and catalyst dosage were studied, and their optimal amounts were found at 60 min, 5.58 and 0.025 g, respectively. A good correlation was found between experimental and predicted responses, confirming the reliability of the model. Incorporation of Ag2O in the structure of composite caused decreasing band gap and its response to visible light. Because a high percentage of sunlight is visible light, hence Ag2O-Bi2O3 nano-composite could be used as an efficient visible light driven photocatalyst for degradation of dye effluents by sunlight. Copyright © 2017 BCREC GROUP. All rights reservedReceived: 15th August 2016; Revised: 20th December 2016; Accepted: 21st December 2016How to Cite: Hosseini, S.A., Saeedi, R. (2017). Photocatalytic Degradation of Methyl Orange on Bi2O3 and Ag2O-Bi2O3 Nano Photocatalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1): 96-105 (doi:10.9767/bcrec.12.1.623.96-105)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.623.96-105

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Study on the treatment of simulated azo dye wastewater by a novel micro-electrolysis filler

Water Science & Technology ◽

10.2166/wst.2019.234 ◽

2019 ◽

Vol 79 (12) ◽

pp. 2279-2288 ◽

Cited By ~ 1

Author(s):

Zhen-Zhu Sun ◽

Zhong-Hai Liu ◽

Le Han ◽

Dong-Ling Qin ◽

Gang Yang ◽

...

Keyword(s):

Activated Carbon ◽

Methyl Orange ◽

Degradation Rate ◽

Ph Value ◽

Aeration Rate ◽

Layer By Layer ◽

Dye Wastewater ◽

Operational Parameters ◽

Initial Ph ◽

New Type

Abstract A new type of iron-copper-carbon (Fe-Cu-C) ternary micro-electrolysis filler was prepared with a certain proportion of iron powder, activated carbon, bentonite, copper powder, etc. The effect of the new type of micro-electrolysis filler on the simulated methyl orange dye wastewater was studied. The effects of various operational parameters, such as reaction time, initial pH value, aeration rate, filler dose and reaction temperature, on the degradation rate of methyl orange were studied to determine the optimum treatment conditions, and the micro-electrolysis filler was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental results show that the degradation rate of 220 mL of simulated dye wastewater with a concentration of 100 mg/L reached 93.41% ± 2.94% after 60 mL/min of aeration, with an initial pH = 2, a dose of 45 g and 125 minutes of reaction at room temperature. The new micro-electrolysis filler has a high degradation rate for methyl orange solution, which is attributed to the iron and activated carbon particles sintered into an integrated structure, which makes the iron and carbon difficult to separate and affects the galvanic cell reaction. The addition of copper also greatly increases the transmission efficiency of electrons, which promotes the reaction. In addition, the surface iron is consumed, the adjacent carbon is stripped layer by layer, and the new micro-electrolytic filler does not easily passivate and agglomerate during its use.

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Heterogeneous electro-Fenton oxidation of azo dye methyl orange catalyzed by magnetic Fe3O4 nanoparticles

Water Science & Technology ◽

10.2166/wst.2016.300 ◽

2016 ◽

Vol 74 (5) ◽

pp. 1116-1126 ◽

Cited By ~ 16

Author(s):

Hao Jiang ◽

Yabing Sun ◽

Jingwei Feng ◽

Jian Wang

Keyword(s):

Methyl Orange ◽

Current Density ◽

Azo Dye ◽

Aeration Rate ◽

Triple Quadrupole Mass Spectrometer ◽

Liquid Chromatograph ◽

Total Organic Carbon Removal ◽

Initial Ph ◽

Catalyst Dosage ◽

Nano Fe3o4

Azo dye methyl orange (MO) degradation by heterogeneous electro-Fenton (EF) with a magnetic nano-Fe3O4 catalyst was investigated. In this study, Fe3O4 was synthesized by a coprecipitation method and characterized by X-ray diffraction and scanning electron microscopy. The influences of the main operating parameters such as current density, pH, catalyst dosage and aeration rate were studied. The results revealed that higher current density, catalyst dosage and aeration rate facilitated the degradation of MO, whereas the degradation efficiency of MO was decreased with an increase in the initial pH. After 90 min EF process, the volume of 500 mL, the initial concentration of 50 mg L−1 MO solution could be degraded by 86.6% with the addition of 1 g L−1 Fe3O4 under the current density of 10 mA cm−2 and pH 3, compared with 69.5% for the electrolytic process alone. Meanwhile, a total organic carbon removal of 32% was obtained, up to 35.5 mg L−1 accumulated H2O2 and less than 3.5 mg L−1 Fe leaching were detected. Moreover, based on the results of natural bond orbital (at B3LYP/6-311G (d, p)) and liquid chromatograph-triple quadrupole mass spectrometer analysis, nine intermediates were identified and the proposed degradation pathways were investigated.

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Treatment of methyl orange dye wastewater by cooperative electrochemical oxidation in anodic–cathodic compartment

Water Science & Technology ◽

10.2166/wst.2012.589 ◽

2013 ◽

Vol 67 (3) ◽

pp. 521-526 ◽

Cited By ~ 4

Author(s):

L. Pang ◽

H. Wang ◽

Z. Y. Bian

Keyword(s):

Methyl Orange ◽

Electrochemical Oxidation ◽

Removal Efficiency ◽

Ph Value ◽

Dye Wastewater ◽

Characteristic Absorption Peak ◽

Divided Cell ◽

Initial Ph ◽

Cathodic Compartment ◽

Degradation Of Methyl Orange

Electrochemical oxidation of methyl orange wastewater was studied using Ti/IrO2/RuO2 anode and a self-made Pd/C O2-fed cathode in the divided cell with a terylene diaphragm. The result indicated that the appropriate rate of feeding air improved the methyl orange removal efficiency. The discoloration efficiency of methyl orange in the divided cell increased with increasing current density. The initial pH value had some effect on the discoloration of methyl orange, which became not obvious when the pH ranged from 2 to 10. However, the average removal efficiency of methyl orange wastewater in terms of total organic carbon (TOC) can reach 89.3%. The methyl orange structure had changed in the electrolytic process, and the characteristic absorption peak of methyl orange was about 470 nm. With the extension of electrolysis time, the concentration of methyl orange gradually reduced; wastewater discoloration rate increased gradually. The degradation of methyl orange was assumed to be cooperative oxidation by direct or indirect electrochemical oxidation at the anode and H2O2, ·OH, O2−· produced by oxygen reduction at the cathode in the divided cell. Therefore, the cooperative electrochemical oxidation of methyl orange wastewater in the anodic–cathodic compartment had better degradation effects.

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Degradation Mechanism of Methyl Orange by Pyrite-Activated Persulfate

10.21203/rs.3.rs-572480/v1 ◽

2021 ◽

Author(s):

Hui Liu ◽

Wenlong BI

Keyword(s):

Methyl Orange ◽

Negative Impact ◽

Tap Water ◽

Degradation Mechanism ◽

Inhibitory Effect ◽

Optimal Dosage ◽

High Concentration ◽

Initial Ph ◽

Advanced Oxidation Technology ◽

Activated Persulfate

Abstract This paper took methyl orange (MO), a typical azo dye, as the target substance to explore the degradation mechanism of pyrite (FeS2)-activated persulfate (PS) by advanced oxidation technology, and response surface methodology was used to determine the optimal dosage of FeS2 and PS. The related experiments were conducted focused on different factors and degradation mechanisms. The results showed that when the initial concentration of MO was 0.1 mM, the pyrite was 1.6 g/L and PS was 1.0 mM, the degradation rate of MO could reach 92.94% in 150 min. In the FeS2/PS system, the main free radical was sulfate radical, which contributed about 22.43% to the degradation of MO, but the hydroxyl radical contributed little. Both pH ≤ 2 and pH ≥ 10 would have an inhibitory effect on the system, and the removal effect of MO was the best at initial pH of 4. The Cl−, HCO3− and H2PO4− might play an important role in the treatment of actual wastewater. This study had shown that HCO3− in a low concentration and Cl− had little effect on the system; H2PO4− and high concentration of HCO3− could inhibit the reaction of the system. By exploring the influence of different water matrices such as tap water, river water, and distilled water, it was found that HCO3− would have a negative impact on the experiment, and the degradation effect was obviously observed when the pH was adjusted to 4. The results can provide technical support for the degradation of pyrite-activated persulfate system in printing and dyeing wastewater.

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Adsorption of Cationic and Anionic Dyes from Aqueous Solution Using Sunflower Husk

Chemistry & Chemical Technology ◽

10.23939/chcht15.04.567 ◽

2021 ◽

Vol 15 (4) ◽

pp. 567-574

Author(s):

Huda A. Jaber ◽

◽

Marwa F. Abdul Jabbar ◽

Keyword(s):

Methyl Orange ◽

Contact Time ◽

Brilliant Green ◽

Kinetic Studies ◽

Anionic Dyes ◽

Time Intervals ◽

Ph Values ◽

Initial Ph ◽

Pseudo Second Order ◽

Adsorbent Dose

The current study deals with the removal of cationic dye (brilliant green) and anionic dye (methyl orange) from wastewater by using sunflower husk as an adsorbent. The operation takes place batch wise by applying several concentrations of the dye solution with various adsorbent amounts, at a range of initial PH values and particle sizes at varying contact time intervals. The percent of dye removed for two dyes increased with increasing time and adsorbent dose and decreased with increasing the dye concentration and particle size. The equilibrium time differed according to conditions used. The optimum removal for brilliant green dye was 98 %, which was achieved at 50 ppm dye concentration, 2 g\l adsorbent dose, 75 µm particles size and pH 7 at contact time of 1 h, compared with low removal for methyl orange that reached 54 % under optimum conditions (dye concentration 10 ppm, adsorbent dose 4 g/l, pH 3 at the same particles size and time). Kinetic studies were conducted and revealed that the adsorption was well defined by pseudo-second order model and could be described by the Langmuir isotherm.

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