Study on Dynamics of Electrochemical Degradation for Chitosan

2011 ◽  
Vol 291-294 ◽  
pp. 1899-1904
Author(s):  
Yong Chun Huang ◽  
Chao Yue Zhao ◽  
Feng Yang ◽  
Ren He
Keyword(s):  
Kinetic Equation ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Electrochemical Degradation ◽  
Nacl Solution ◽  
Chitosan Concentration ◽  
Nacl Concentration

The electrochemical degradation of chitosan was studied with using graphite as anode and cathode, NaCl solution as supporting electrolyte. The effects of current density, temperature, NaCl concentration, pH, chitosan concentration on the degradation dynamics were investigated. It was shown that the electrochemical degradation of chitosan obeys the rule of random degradation, and the kinetic equation was established.

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.

Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water

2014 ◽  
Vol 278 ◽  
pp. 221-226 ◽  
Author(s):  
Fernando L. Guzmán-Duque ◽  
Ricardo E. Palma-Goyes ◽  
Ignacio González ◽  
Gustavo Peñuela ◽  
Ricardo A. Torres-Palma
Keyword(s):  
Anode Material ◽  
Organic Compounds ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Electrochemical Degradation

Electrochemical Degradation of Phenol Using the Oxygen Diffusion Cathode in an Undivided Cell

2011 ◽  
Vol 183-185 ◽  
pp. 575-579
Author(s):  
Hui Wang ◽  
Zhao Yong Bian ◽  
Guang Lu ◽  
Xiang Jia Wei ◽  
Xiu Juan Yu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Supporting Electrolyte ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Degradation Pathway ◽  
Phenol Removal ◽  
Electrochemical Degradation ◽  
Undivided Cell

Electrochemical degradation of phenol was studied in an undivided cell with a Ti/IrO2/RuO2 anode and a carbon/polytetrafluoroethylene (C/PTFE) O2-fed cathode which produced hydrogen peroxide (H2O2) by the electro-reduction of dissolved oxygen. The effect of current density, supporting electrolyte concentration and initial pH on the removal efficiency of phenol were investigated systematically. Results indicated that the optimal removal efficiency of phenol was achieved under the conditions of current density of 39 mA/cm2 and supporting electrolyte concentration of 0.02 mol/L. The phenol removal efficiency in the neutral condition was higher than that of acidic and basic conditions. The chemical oxygen demand (COD) and total organic carbon (TOC) removal achieved 71.6% and 63.6% for 100 min’s electrolysis, respectively. Benzoquinone, maleic acid, oxalic acid, acetic acid and formic acid were identified as intermediates by HPLC. A general phenol degradation pathway involving all these intermediates was proposed.

Electrochemical Degradation of Acid Blue 41 on Ti/Sb-SnO2 Anodes

2012 ◽  
Vol 518-523 ◽  
pp. 2505-2508
Author(s):  
Xiao Xing Zhang ◽  
Na Niu ◽  
Ya Qiong Wang ◽  
Wen Lin Xu
Keyword(s):  
Current Density ◽  
Supporting Electrolyte ◽  
Degradation Process ◽  
Cod Removal ◽  
Color Removal ◽  
Electrochemical Degradation ◽  
Precursor Method ◽  
Chromophore Group ◽  
Instantaneous Current ◽  
Acid Blue

The electrochemical degradation of the wastewater of acid blue 41 was studied with Ti/Sb-SnO2 as an anode in which the Sb-SnO2 coating was prepared with a polymeric precursor method. The conversion of acid blue 41 was carried out under galvanostatic control. The effects of current density, initial concentration of acid blue 41 and the concentration of supporting electrolyte on color removal, COD removal and instantaneous current efficiency (ICE) were investigated. The experimental results show that the color removal and COD removal enhance with increasing current density, but ICE decreases. Acid blue 41 can firstly be oxidized by the destroying the conjugated chromophore group and it is difficult that the intermediates produced during the degradation process of cid blue 41 is further degraded.

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.

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.

scholarly journals Investigation of NiFe-Based Catalysts for Oxygen Evolution in Anion-Exchange Membrane Electrolysis

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1720
Author(s):  
Sabrina Campagna Zignani ◽  
Massimiliano Lo Faro ◽  
Stefano Trocino ◽  
Antonino Salvatore Aricò
Keyword(s):  
Single Cell ◽  
Anion Exchange ◽  
Oxygen Evolution ◽  
Current Density ◽  
Electrochemical Behaviour ◽  
Stress Test ◽  
Supporting Electrolyte ◽  
Anion Exchange Membrane ◽  
Operating Conditions ◽  
Exchange Membrane

NiFe electrodes are developed for the oxygen evolution reaction (OER) in an alkaline electrolyser based on an anion exchange membrane (AEM) separator and fed with diluted KOH solution as supporting electrolyte. This study reports on the electrochemical behaviour of two different NiFe-oxide compositions (i.e., Ni1Fe1-oxide and Ni1Fe2-oxide) prepared by the oxalate method. These catalysts are assessed for single-cell operation in an MEA including a Sustainion™ anion-exchange membrane. The electrochemical polarization shows a current density of 650 mA cm−2 at 2 V and 50 °C for the Ni1Fe1 anode composition. A durability test of 500 h is carried out using potential cycling as an accelerated stress-test. This shows a decrease in current density of 150 mA cm−2 mainly during the first 400 h. The performance achieved for the anion-exchange membrane electrolyser single-cell based on the NiFeOx catalyst appears promising. However, further improvements are required to enhance the stability under these operating conditions.

Effect of Bath Formulation and Plating Current Density on Electrodeposited Zinc Anode’s Capacity in Zinc-Air Cell

2012 ◽  
Vol 576 ◽  
pp. 484-487
Author(s):  
Raihan Othman ◽  
Farouq Ahmat ◽  
Muhd Amlie Ibrahim ◽  
Assayidatul Laila Nor Hairin ◽  
Hanafi Ani Mohd
Keyword(s):  
Ammonium Chloride ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Constant Load ◽  
Total Charge ◽  
Electrolytic Bath ◽  
Plating Bath ◽  
Zinc Anode ◽  
Discharge Performance ◽  
Cell Discharge

Zinc anode is electrodeposited from a 2-M zinc chloride electrolytic bath with varying ammonium chloride supporting electrolyte concentrations (0-5 M) and plating current density (0.1 – 0.6 A cm-2). The total charge quantity supplied during electrodeposition is fixed at 150 mAh. Alkaline zinc-air cell is fabricated using the electrodeposited zinc anode and characterized according to its discharge capacity at constant load current of 20 mA. The effect of various qualities of zinc electrodeposits on the cell discharge performance is discussed. It is found that zinc electrodeposits prepared from electrolytic bath of 5-M ammonium chloride and 0.5 A cm-2 plating current density produced zinc-air cell with the highest output energy i.e. 24 mWh. We observe that the influence of plating current density is more prominent than the plating bath formulation on the zinc anode performance in the cell.

Controlling factors in localised corrosion morphologies observed for magnesium immersed in chloride containing electrolyte

2015 ◽  
Vol 180 ◽  
pp. 313-330 ◽  
Author(s):  
Geraint Williams ◽  
Nick Birbilis ◽  
H. Neil McMurray
Keyword(s):  
Current Density ◽  
Radial Growth ◽  
Cathodic Current Density ◽  
Nacl Solution ◽  
High Concentration ◽  
Cathodic Current ◽  
Density Distributions ◽  
Filiform Corrosion ◽  
Density Values ◽  
Current Densities

The early stages of localised corrosion affecting magnesium (Mg) surfaces when immersed in aqueous sodium chloride (NaCl) solutions involves the propagation of dark regions, within which both anodic metal dissolution and cathodic hydrogen evolution occur. For nominally “pure” Mg, these dark areas can either take the form of discs which expand radially with time, or filiform-like tracks which lengthen with time. For Mg surfaces which display disc-form corrosion features in concentrated NaCl electrolyte, a transition to filiform corrosion (FFC) is observed as the concentration is decreased, indicating ohmic constraints on radial propagation. A similar effect is observed when Mg specimens of different iron impurity are immersed in a fixed, high concentration NaCl solution, where disc-form corrosion is observed on samples having ≥280 ppm Fe, but FFC predominates at ≤80 ppm Fe. An in situ scanning vibrating electrode technique (SVET) is used to determine current density distributions within the propagating corrosion features. Cathodic current density values of between −100 and −150 A m−2 measured in central areas of disc-like features are sufficient to sustain the radial growth of a local anode at the perimeter of the discs. However, for high purity Mg specimens (≤80 ppm Fe), cathodic current densities of −10 A m−2 or less are measured over FFC affected regions, indicating that linear propagation arises when there is insufficient cathodic current produced on the corroded surface to sustain radial growth. The results are consistent with surface control of localised corrosion propagation in concentrated electrolyte, but ohmic control in dilute, lower conductivity NaCl solution.

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.

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