Electrochemical Oxidation of Azo Dye Wastewater Using Graphene-Based Electrode Materials

2019 ◽  
Vol 19 (11) ◽  
pp. 7308-7314
Author(s):  
Jinyan Li ◽  
Qingsong Guan ◽  
Junming Hong ◽  
Chang-Tang Chang
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Electrode Materials ◽  
Supporting Electrolyte ◽  
Performance Comparison ◽  
Carbon Cloth ◽  
Reactive Black 5 ◽  
Dye Wastewater ◽  
Composite Electrodes ◽  
Initial Concentration

Composite electrodes with different graphene (GN)/TiO2 ratios and nano-activated carbon electrodes were prepared for electrocatalytic performance comparison. The electrodes were loaded with platinum (Pt) by use of chloroplatinic acid to promote their performance. Reactive Black 5 (RBk5) dye wastewater was treated as a challenging pollutant by use of advanced electrochemical oxidation technology. The composite materials were characterized by Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Disperse Spectroscopy (EDS). Results showed that the graphene electrode was prepared successfully and verified because all elements were uniformly loaded on the conductive carbon cloth. The effects of several operating parameters including material types, pH, initial concentration of RBk5, and current density on the removal performance of RBk5 were also assessed. The supporting electrolyte was NaCl solution of 1 g L−1. The concentration of RBk5 was detected using an ultraviolet spectrophotometer with a detection wavelength of 600 nm. The optimum parameters of the experiment were GN/TiO2 ratio of 1:4 and pH of 6.6. The removal efficiency of RBk5 could be higher than 95% under an initial concentration of RBk5 of 5 ppm and a current density of 2.5 mA·cm-2 when reaction time was 30 min.

Study on Electrochemical Degradation of Acid Scarlet 3R

2011 ◽  
Vol 71-78 ◽  
pp. 3071-3074
Author(s):  
Jun Sheng Hu ◽  
Yue Li ◽  
Zhuo Wang
Keyword(s):  
Current Density ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Removal Rate ◽  
Supporting Electrolyte ◽  
Color Removal ◽  
Alkaline Condition ◽  
Dye Wastewater ◽  
Initial Concentration ◽  
Initial Ph

Based on a static experiment, this study researched the electrochemical oxidation process of simulated dye wastewater containing Acid Scarlet 3R in the two-dimensional electrolysing cell. This experiment investigated the effect of such various factors as current density, initial concentration, supporting electrolyte concentration, and the initial pH value on the color removal. The results of the experiment clearly indicated that the rate of color removal increased when the current density was increasing gradually; it decreased when the initial concentration was increasing; it originally increased and then decreased when concentration of electrolytes was increasing; alkaline condition was not conducive to the removal of color, and the effect of decolorization was better under an acid condition than under an alkaline condition. The optimum condition of disposing of dye wastewater is when the current density is 7Am/cm², electrolyte concentration is 0.04mol/L, pH=2.5, under the condition of which the color removal rate could be 96.06%.

Study on the Treatment of High Concentration Dye Wastewater on Modified Active Carbon Cloth Electrode

2011 ◽  
Vol 347-353 ◽  
pp. 1869-1873 ◽  
Author(s):  
Hong Xia
Keyword(s):  
Electrochemical Oxidation ◽  
Active Carbon ◽  
Removal Rate ◽  
Modified Electrodes ◽  
Carbon Cloth ◽  
Dye Wastewater ◽  
Composite Electrodes ◽  
High Concentration ◽  
Scanning Electronmicroscopy ◽  
Oxidation System

In this study, for the first time nanostructured TiO2 and Fe2O3 was loaded on active carbon cloth (ACC) as electrodes to be used in an electrochemical oxidation system. This novel TiO2-ACC and Fe2O3 / TiO2-ACC composite electrodes(or modified electrodes) were characterized by scanning electronmicroscopy (SEM)and cyclic voltammetry(CV).During the degradation of dye wastewater, electrochemical oxidation system with TiO2-ACC and Fe2O3 / TiO2-ACC electrodes showed much higher activity than with ACC electrodes. The system with Fe2O3 / TiO2-ACC electrodes acquired the best COD removal: the COD of wastewater decreased from 33000 mg/L to 8700mg/L. The removal rate of COD reached 74%, which was 19% higher than ACC system.

The electrochemical degradation of the metronidazole (MNZ) antibiotic using electrochemical oxidation on a stainless steel316 coated with beta lead oxide (SS316/β-PbO2) anode

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Sommayeh Saadi ◽  
Parisa Mahmoudpoor Moteshaker ◽  
Seyed Ehsan Rokni ◽  
Ghobad Ahmadidoust ◽  
Narges Farnoodian ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Lead Oxide ◽  
Supporting Electrolyte ◽  
Pharmaceutical Products ◽  
Electrochemical Process ◽  
Electrochemical Degradation ◽  
Effective Parameters ◽  
Electro Deposition ◽  
X Ray

AbstractMetronidazole (MNZ) is one of the pharmaceutical products which is considered as one of the most important pollutants in the environment due to its wide use and resistance to biodegradation. Hence, the purpose of this study is the optimization of the electrochemical degradation of the metronidazole (MNZ) antibiotic using electrochemical oxidation on a stainless steel316 coated with beta lead oxide (SS316/β-PbO2) anode. In the studied electrochemical process, the response surface methodology (RSM) involving a five-level ((pH (A) and electrolysis time (B), current density (C), and MNZ concentration (D)). The central composite design (CCD) was employed for optimizing and modeling of the electrochemical process in the degradation of MNZ. The preparation of SS316/β-PbO2 anode was accomplished using the electro-deposition method. Scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) analyses were conducted for accurate evaluation and characterization of the coated electrode. The effect of influencing factors on electrochemical degradation of MNZ was studied, and the highest MNZ degradation efficiency was observed to be 98.88% after 120 min under the optimal conditions including the supporting electrolyte concentration of 1.0 g/100 cc, the initial MNZ concentration of 30.1 mg/L, pH of 4 and the current density of 9.99 mA/cm2. The linear regression coefficient (R2) between experiments and different response values in the model was 0.99. Moreover, the statistical analysis of the results indicated that in the range studied, the most effective parameters in MNZ degradation are MNZ concentration and pH. In general, it can be concluded that the electrochemical process using SS316/β-PbO2 anode can effectively eliminate metronidazole, and it can be considered as an efficient method in the degradation of various pollutants.

scholarly journals Ecotoxicological Evaluation of Methiocarb Electrochemical Oxidation

2020 ◽  
Vol 10 (21) ◽  
pp. 7435
Author(s):  
Annabel Fernandes ◽  
Christopher Pereira ◽  
Susana Coelho ◽  
Celso Ferraz ◽  
Ana C. Sousa ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Removal Rate ◽  
Supporting Electrolyte ◽  
Ecological Effects ◽  
Applied Current ◽  
Boron Doped Diamond ◽  
Experimental Conditions ◽  
Applied Current Density ◽  
Toxicity Reduction

The ecotoxicity of methiocarb aqueous solutions treated by electrochemical oxidation was evaluated utilizing the model organism Daphnia magna. The electrodegradation experiments were performed using a boron-doped diamond anode and the influence of the applied current density and the supporting electrolyte (NaCl or Na2SO4) on methiocarb degradation and toxicity reduction were assessed. Electrooxidation treatment presented a remarkable efficiency in methiocarb complete degradation and a high potential for reducing the undesirable ecological effects of this priority substance. The reaction rate followed first-order kinetics in both electrolytes, being more favorable in a chloride medium. In fact, the presence of chloride increased the methiocarb removal rate and toxicity reduction and favored nitrogen removal. A 200× reduction in the acute toxicity towards D. magna, from 370.9 to 1.6 toxic units, was observed for the solutions prepared with NaCl after 5 h treatment at 100 A m−2. An increase in the applied current density led to an increase in toxicity towards D. magna of the treated solutions. At optimized experimental conditions, electrooxidation offers a suitable solution for the treatment and elimination of undesirable ecological effects of methiocarb contaminated industrial or agricultural wastewaters, ensuring that this highly hazardous pesticide is not transferred to the aquatic environment.

Influence of Different Anode Materials on the Treatment of Azo Dyed Wastewater by Electrochemical Method

2011 ◽  
Vol 368-373 ◽  
pp. 3221-3225 ◽  
Author(s):  
Yu Hua Zhao ◽  
De Cai Jin ◽  
Xiao Yi Cang ◽  
Jie Li
Keyword(s):  
Current Density ◽  
Electrochemical Method ◽  
Anode Materials ◽  
Electrode Materials ◽  
Hydraulic Retention Time ◽  
Dye Wastewater ◽  
Carbon Felt ◽  
Removal Ratio ◽  
Iron Anode ◽  
The Impact

The paper aimed to compare removal effects in azo dyed wastewater by electrochemical method with different anode materials, and explored the impact of current density on the treatment effect with different electrode materials. Carbon felt, aluminum, iron were served as the anodes, graphite columns were served as cathodes of apparatus. The hydraulic retention time was 12 hours, current density is respectively 0.01, 0.024, 0.048, 0.071, 0.083 mA/cm² for the test. The results showed that the removal ratio of dye concentration had a rising trend as the current density increased. The removal ratio by the apparatus with iron anode was best, aluminum second. When the current density was 0.083 mA/㎝², the removal ratio of dye concentration was 97.63%, but the other two were only 62.01% and 29.05%. The removal of colority and COD with aluminum anode was best, when the current density was 0.048mA/㎝², the removal ratio of colority and COD was respectively 71.39% and 44.41%. Thus, the removal of dye concentration by electrochemical method with iron anode was best, while aluminium anode was good for colority and COD. The treatment of azo dye wastewater by carbon felt anode electrochemical didn’t get significant effect.

Electrocatalytic hydrogenation of phenol on various electrode materials

1997 ◽  
Vol 75 (12) ◽  
pp. 1862-1867 ◽  
Author(s):  
Anna Martel ◽  
Behzad Mahdavi ◽  
Jean Lessard ◽  
Hugues Ménard ◽  
Louis Brossard
Keyword(s):  
Sodium Chloride ◽  
Current Efficiency ◽  
Raney Nickel ◽  
Current Density ◽  
Electrode Materials ◽  
Supporting Electrolyte ◽  
Current Control ◽  
Electrocatalytic Hydrogenation ◽  
Nickel Particles ◽  
A Current

The electrocatalytic hydrogenation (ECH) of phenol was investigated at room temperature under galvanostatic control in aqueous sulfuric acid solutions on platinized platinum (Pt/Pt) electrodes and on composite Rh/Ni and Ru/Ni electrodes consisting of rhodium or ruthenium chemically deposited on nickel particles dispersed in a lanthanum polyphosphate matrix. The order of electrocatalytic activity at a current density (based on the geometric area) of 1 mA/cm2 was found to be Ru/Ni > Pt/Pt > Rh/Ni. The efficiency decreased with increased current density. For the Ru/Ni electrodes, the efficiency increased with the percentage of Ru (2.3 to 5%). On Ru 5%/Ni electrodes and at a current density of 5 mA/cm2, cyclohexanol was obtained with a high selectivity of 91 % and a current efficiency of 23% after 94% conversion. In neutral aqueous boric acid containing sodium chloride as supporting electrolyte, the Rh/Ni and Ru/Ni electrodes showed very low activity. The influence of the supporting electrolyte, periodic current control, and temperature was studied in the neutral medium with composite Raney nickel (RaNi) electrodes consisting of Raney nickel particles dispersed in a nickel matrix. At 60 °C and a current density of 10 mA/cm2, the selectivity of cyclohexanol formation was 100% with a 11% current efficiency after 92% conversion with sodium chloride as supporting electrolyte. Keywords: electrocatalytic hydrogenation, phenol, ruthenium on nickel cathodes, rhodium on nickel cathodes, Raney nickel cathodes.

Facile synthesis and characterization of the Mn-MOF electrode material for flexible supercapacitors

2021 ◽  
pp. 1-19
Author(s):  
Yanhong Liu ◽  
Jiahong Liu ◽  
Yijun Cao ◽  
Wei Shang ◽  
Ning Peng ◽  
...  
Keyword(s):  
Current Density ◽  
Electrode Material ◽  
High Performance ◽  
Electrode Materials ◽  
Metal Organic Frameworks ◽  
Charge Transfer Resistance ◽  
Carbon Cloth ◽  
Flexible Electrode ◽  
Transfer Resistance ◽  
Metal Organic

Abstract Metal-organic frameworks (MOFs) due to their porosity and well-defined structures are considered to be very promising electrode materials for the construction of high-performance supercapacitor. In this paper, manganese-based metal organic frameworks (Mn-MOF) were prepared on the surface of carbon cloth (CC) by hydrothermal method. The morphology and structure of the electrode material were characterized by SEM, XRD, FT-IR, and XPS. Its electrochemical studies show that the Mn-MOF electrode materials exhibit low charge transfer resistance, the excellent specific capacitance of 433.5 mF·cm−2 in 1.0 M Na2SO4 aqueous solution at the current density of 0.8 mA·cm−2. It is noteworthy that the flexible electrode has excellent cycle stability and 105% capacitance retention even after 5000 cycles at a current density of 5 mA·cm−2. The high electrochemical performance of Mn-MOF/CC flexible electrode materials can be attributed to its three-dimensional porous structure.

Capacitive performance of electrochemically deposited Co/Ni oxides/hydroxides on polythiophene-coated carbon-cloth

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gülten Atun ◽  
Filiz Şahin ◽  
Elif Türker Acar ◽  
Sinem Ortaboy
Keyword(s):  
Layered Double Hydroxide ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Supporting Electrolyte ◽  
Carbon Cloth ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Electrochemically Deposited ◽  
Double Hydroxide ◽  
Coated Carbon

Abstract Cobalt, nickel, and their mixed hydroxides were electrochemically deposited on polythiophene-coated carbon-cloth substrate to develop new pseudo-capacitive electrodes for energy storage devices. Thiophene was electro-polymerized on carbon-cloth by the potentiodynamic method in acetonitrile containing 1-butyl-2,3-dimethylimidazolium hexafluorophosphate ionic-liquid as supporting electrolyte. The scanning-electron-microscopy images imply that flower-like Co(OH)2 microstructures deposited on bamboo-like polythiophene coatings on carbon-fibers but they are covered by net curtain like thin Ni(OH)2 layer. The Co-Ni layered-double-hydroxide deposited from their equimolar sulfate solutions is composed of large aggregates. The electron-dispersive-spectrum exhibits that Co/Ni ratio equals unity in the layered-double-hydroxide. The capacitances of Co, Ni, and Co-Ni hydroxide-coated PTh electrodes are 100, 569, and 221 F/g at 5 mA/cm2 in 1 M KOH solution, respectively. Their corresponding oxides obtained by calcination at 450 °C in de-aerated medium possess higher capacitance up to 911, 643, and 696 F/g at 2 A/cm2. The shape of cyclic-voltammetry and galvanostatic-charge-discharge curves, as well as the Nyquist plots derived from electrochemical-impedance-spectroscopy measurements, reveal that hydroxide coatings on the polythiophene-coated carbon-cloth are more promising electrode materials for supercapacitor applications. The mixed hydroxide-coated electrode shows good cyclic stability of 100% after 400 cycles at 5 mA/cm2.

Electrochemical degradation of 4-chlorophenol in aqueous solution using modified PbO2 anode

2012 ◽  
Vol 66 (11) ◽  
pp. 2468-2474 ◽  
Author(s):  
X. Y. Duan ◽  
F. Ma ◽  
L. M. Chang
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Oxidation ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Positive Influence ◽  
Applied Current ◽  
Applied Current Density ◽  
Toc Removal ◽  
First Order Kinetics ◽  
Pbo2 Electrode

The electrochemical oxidation of 4-chlorophenol (4-CP) in aqueous solution was studied by electrochemical oxidation using modified PbO2 electrode as anode. The influence of several operating parameters, such as initial 4-CP concentration, applied current density, and supporting electrolyte (Na2SO4) concentration was investigated. Ultraviolet spectroscopy and total organic carbon (TOC) measurements were conducted to study the kinetics of 4-CP electrochemical reaction and the mineralization efficiency of 4-CP. The experimental results showed that the 4-CP degradation always followed a pseudo-first-order kinetics. The higher mineralization of 4-CP and the lower current efficiency (CE) were obtained by the lower initial 4-CP concentration. The applied current density showed a positive influence on the degradation of 4-CP and the removal of TOC, but a higher applied current density led to a lower CE. Although Na2SO4 concentration of 0.05 M resulted in a higher 4-CP and TOC removal, the result of one-way analysis of variance (ANOVA) indicates that Na2SO4 concentration is not the significant parameter for 4-CP removal in electrochemical oxidation.

Electrochemical oxidation pretreatment of refractory organic pollutants

1997 ◽  
Vol 36 (2-3) ◽  
pp. 123-130 ◽  
Author(s):  
Li-Choung Chiang ◽  
Juu-En Chang ◽  
Shu-Chuan Tseng
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Oxidation Process ◽  
Supporting Electrolyte ◽  
Chloride Concentration ◽  
Gel Permeation Chromatography ◽  
Organic Halogen ◽  
Removal Efficiencies ◽  
Refractory Organic Pollutants ◽  
Microtox Test

Refractory pollutants, including lignin, tannic acid, chlortetracycline, and EDTA, were destroyed by an electrochemical oxidation method to evaluate the applicability of this method for industrial wastewater pretreatment. Operation parameters, such as supporting electrolyte, current density, and electrolyte concentration, have been investigated for their influences on COD removal efficiencies during electrolysis. In addition, gel permeation chromatography (GPC), Microtox test, and total organic halogen (TOX) analyses were performed to monitor the changes of organic characteristics of these refractory pollutants. Experimental results show that, among sulfate, nitrate, and chloride, chloride was the best supporting electrolyte, and during electrolysis, both COD and color removal efficiencies were improved by increasing current density and chloride concentration. From GPC analysis results, the electrochemical oxidation process readily destroys high-molecular-weight (HMW) organics. Microtox test results also show that the process can reduce the toxicity of these refractory organic compounds. In addition, TOX concentrations were found to increase at the beginning but then decline during the electrolysis. The above results suggest that the electrochemical oxidation process, which has good efficacy for detoxification and destruction of refractory pollutants, is a promising method for wastewater pretreatment.

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