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

2016 ◽  
Vol 74 (5) ◽  
pp. 1116-1126 ◽  
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.

Dye Wastewater Treatment by Means of Electrochemistry in Diaphragm Electrolyzer

2012 ◽  
Vol 178-181 ◽  
pp. 557-561
Author(s):  
Jun Sheng Hu ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Xue Dong Ren
Keyword(s):  
Current Density ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Aeration Rate ◽  
Alkaline Condition ◽  
Porous Graphite ◽  
Initial Ph ◽  
Cathode Area ◽  
Simulated Wastewater ◽  
Diaphragm Cell

In diaphragm cell, by using the porous graphite as anode, ACF as the cathode, acid scarlet 3R as simulated wastewater, the experiment researched into the effect of current density, electrolyte concentration, aeration rate and the initial pH value on the color removal of wastewater. The results show that the decolourization efficiency increased gradually when the applied current density increases, but the trend will slow down when current density exceeds a certain value. The decolourization efficiency is proved to be first increases then decreases with increased electrolyte concentration and aeration rate, both excessively high and low electrolyte concentration are unfavorable to the removal of wastewater, however the aeration effect is smaller. The effect on decolorization is greater in acid condition than in alkaline condition. As the diaphragm, electrolyzer resistance increase, its average decolourization efficiency is lower than without diaphragm cell, and the decolourization efficiency of cathode area is significantly higher than the anode area.

scholarly journals Decoloration of waste PET alcoholysis liquid by an electrochemical method

2018 ◽  
Vol 77 (10) ◽  
pp. 2463-2473
Author(s):  
Yanyan Li ◽  
Mengjuan Li ◽  
Jing Lu ◽  
Xiaoqiang Li ◽  
Mingqiao Ge
Keyword(s):  
Current Density ◽  
Degradation Mechanism ◽  
Statistical Design ◽  
Optimal Conditions ◽  
Liquid Chromatography Mass Spectrometry ◽  
Visible Absorption ◽  
Initial Ph ◽  
Predicted Model ◽  
Catalyst Dosage ◽  
Main Operating

Abstract Disperse Red 60 simulated polyester alcoholysis liquid decoloration by electro-Fenton with Fe3O4 catalyst was studied. The influences of the main operating parameters such as catalyst dosage (0.3–0.9 g/L), current density (60–120 mA/cm2) and pH (1–7) were optimized by response surface methodology (RSM) based on Box–Behnken surface statistical design (BBD). In optimal conditions, the initial concentration of 25 mg/L disperse red polyester alcoholysis liquid was catalyzed by 0.6 g/L Fe3O4, and the decoloration efficiency was 97.18% with the current density of 90 mA/cm2 and initial pH of 4.6. There was a relative error of 1.18% with the predicted model when the predictive value was 98.25% under the same conditions. In addition, ultraviolet-visible absorption spectra (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to study the degradation mechanism during decoloration. The intermediates were identified and the proposed degradation pathways were investigated by liquid chromatography-mass spectrometry (LC-MS) analysis.

scholarly journals Combination of novel coalescing oil water separator and electrocoagulation technique for treatment of petroleum compound contaminated groundwater

2017 ◽  
Vol 76 (1) ◽  
pp. 57-67
Author(s):  
Sepideh Oladzad ◽  
Narges Fallah ◽  
Bahram Nasernejad
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Aeration Rate ◽  
Contaminated Groundwater ◽  
Second Phase ◽  
Optimum Conditions ◽  
Water Separator ◽  
Initial Ph ◽  
Oil Water ◽  
Sedimentation Time

In the present study a combination of a novel coalescing oil water separator (COWS) and electrocoagulation (EC) technique was used for treatment of petroleum product contaminated groundwater. In the first phase, COWS was used as the primary treatment. Two different types of coalescing media and two levels of flow rates were examined in order to find the optimum conditions. The effluent of COWS was collected in optimum conditions and was treated using an EC process in the second phase of the research. In this phase, preliminary experiments were conducted in order to investigate the effect of EC reaction time and sedimentation time on chemical oxygen demand (COD) removal efficiency. Best conditions for EC reaction time and sedimentation time were obtained to be 5 min and 30 min, respectively. Response surface methodology was applied to evaluate the effect of initial pH, current density and aeration rate on settling velocity (Vs) and effluent COD. The optimum conditions, for achieving maximum values of Vs as well as the values of effluent COD, in the range of results were obtained at conditions of 7, 34 mA·cm−2 and 1.5 L·min−1 for initial pH, current density and aeration rate, respectively.

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

2019 ◽  
Vol 79 (12) ◽  
pp. 2279-2288 ◽  
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.

scholarly journals Electrochemical Treatment of Water Contaminated with Methylorange

2016 ◽  
Vol 15 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Martin Valica ◽  
Stanislav Hostin
Keyword(s):  
Methyl Orange ◽  
Current Density ◽  
Electrode Material ◽  
Azo Dye ◽  
Dye Removal ◽  
Treatment Time ◽  
Electrochemical Treatment ◽  
Electrochemical Degradation ◽  
Time Duration ◽  
Electro Oxidation

AbstractThis study examines electrochemical degradation of water artificially contaminated by azo dye Methyl Orange (MO). Degradation is based on chemical electro-oxidation of MO molecules. Graphite was used as an electrode material for electrochemical oxidation of MO. In this work, the different operative parameters (electric current, NaCl content) and their effect on effectiveness as well as the treatment time/duration of MO degradation were tested. The highest dye removal (91.0 %) was obtained during the electrolysis at current density 3.032 mA/cm2, electrolyte with the content of NaCl 4 g/dm3 (NaCl) and the treatment time 35 min.

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

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zahia Benredjem ◽  
Karima Barbari ◽  
Imene Chaabna ◽  
Samia Saaidia ◽  
Abdelhak Djemel ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Current Density ◽  
Advanced Oxidation Processes ◽  
Degradation Rate ◽  
Supporting Electrolyte ◽  
Advanced Oxidation ◽  
Comparative Investigation ◽  
Oxidation Processes ◽  
The Comparative Study ◽  
Kinetics Of

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.

SUBMERGED CITRIC ACID FERMENTATION OF SUGAR BEET MOLASSES: INCREASE IN SCALE

1955 ◽  
Vol 1 (5) ◽  
pp. 299-311 ◽  
Author(s):  
R. Steel ◽  
C. P. Lentz ◽  
S. M. Martin
Keyword(s):  
Citric Acid ◽  
Scale Up ◽  
Aeration Rate ◽  
Small Scale ◽  
Acid Fermentation ◽  
Inoculum Level ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Beet Molasses ◽  
Initial Ph

Factors affecting the production of citric acid in the submerged fermentation of ferrocyanide-treated beet molasses by Aspergillus niger were studied in 2.5 and 36 liter fermenters. The small fermenters were used to determine the effects of changes in sterilization technique, phosphate supplement, ferrocyanide treatment, inoculum level, initial pH, fermentation temperature, and aeration rate. The relation between ferrocyanide concentration and inoculum level was also studied. Four different samples of molasses were fermented successfully. An average yield of 8.2% citric acid (64% conversion) was obtained from 51 small-scale fermentations. Comparable yields were obtained in the large fermenters under comparable conditions. Most of the information obtained with the small fermenters was applicable to the larger-scale fermenters, but in the latter the fermentation was significantly more stable. Aeration was the main problem in the scale-up and aeration rates approximately double those calculated on a fermenter cross-sectional area basis were required for comparable results in the large fermenters.

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

2010 ◽  
Vol 36 (9) ◽  
pp. 995-1001 ◽  
Author(s):  
H. Y. He ◽  
W. X. Dong ◽  
G. H. Zhang
Keyword(s):  
Methyl Orange ◽  
Initial Ph

Electrochemical Treatment of Simulated Dye Wastewater

2012 ◽  
Vol 441 ◽  
pp. 555-558
Author(s):  
Feng Tao Chen ◽  
San Chuan Yu ◽  
Xing Qiong Mu ◽  
Shi Shen Zhang
Keyword(s):  
Current Density ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Dye Wastewater ◽  
Electrolysis Time ◽  
Electrochemical Degradation ◽  
Mild Conditions ◽  
Thermal Decomposition Method ◽  
Initial Ph ◽  
Effects Of Ph

The Ti/SnO2-Sb2O3/PbO2 electrodes were prepared by thermal decomposition method and its application in the electrochemical degradation of a heteropolyaromatic dye, Methylene blue (MB), contained in simulated dye wastewater were investigated under mild conditions. The effects of pH, current density and electrolysis time on de-colorization efficiency were also studied. Chemical oxygen demand (COD) was selected as another parameter to evaluate the efficiency of this degradation method on treatment of MB wastewater. The results revealed that when initial pH was 6.0, current density was 50 mA·cm2, electrolysis time was 60 min, Na2SO4 as electrolyte and its concentration was 3.0 g·dm3, the de-colorization and COD removal efficiency can reach 89.9% and 71.7%, respectively.

Kinetics Studies for Catalytic Oxidation of Methyl Orange over the Heterogeneous Fe/Beta Catalysts

2013 ◽  
Vol 807-809 ◽  
pp. 361-364
Author(s):  
Fang Guo ◽  
Jun Qiang Xu ◽  
Jun Li
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Reaction Mechanism ◽  
Methyl Orange ◽  
Incipient Wetness Impregnation ◽  
Kinetics Studies ◽  
Optimum Reaction ◽  
Catalyst Dosage ◽  
Oxidation Degradation ◽  
Degradation Of Methyl Orange

The Fe/Beta catalysts were prepared by conventional incipient wetness impregnation. The catalysis oxidation degradation of methyl orange was carried out in catalyst and H2O2 process. The results indicated that the catalyst and hydrogen peroxide were more benefit to degradation of methyl orange. The reaction condition was optimized. The optimum reaction process was as follow: iron amount of catalyst was 1.25%, the catalyst dosage and H2O2 concentration was 1 mg/L and 1.5 mg/L, and reaction temperature was 70 °C. The apparent activation energy (65 KJ/mol) was obtained according to the arrhenius formula, which was benefit to study the reaction mechanism.

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