Decolorization of reactive bright red K2G dye: electrochemical process catalyzed by manganese mineral

2002 ◽  
Vol 46 (11-12) ◽  
pp. 133-138
Author(s):  
H.-J. Liu ◽  
J.-H. Qu
Keyword(s):  
Current Density ◽  
Ph Value ◽  
Ph Effect ◽  
Electrochemical Process ◽  
Diffraction Spectrum ◽  
Manganese Mineral ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Density Concentration ◽  
Main Component

This paper presents the results of the decolorization of azo dye K2G by the electrochemical process catalyzed by manganese mineral. It is proved that the MnOOH(s), main component of the manganese mineral, can catalyze the electrochemical process and enhance the decolorization efficiency. X-ray powder diffraction spectrum shows that the content of MnOOH(s) has not been changed at the end of the reaction. The effects of initial pH value, current density, concentration of electrolyte on the decolorization efficiency of the dye were investigated in detail. The initial pH effect on the decolorization efficiency of K2G dye is found not to be significant. The optimum current density is 0.26A/dm2. In addition, a proposed catalyzing mechanism of manganese mineral is discussed in this paper.

Electrochemical Disintegration of Activated Sludge Using Ti/RuO2 Anode

2014 ◽  
Vol 567 ◽  
pp. 44-49 ◽  
Author(s):  
Gan Chin Heng ◽  
Mohamed Hasnain Isa
Keyword(s):  
Current Density ◽  
Biological Treatment ◽  
Ph Value ◽  
Electrochemical Process ◽  
Operating Conditions ◽  
Electrolysis Time ◽  
Initial Ph ◽  
Electrode Surface Morphology ◽  
Alkaline Range ◽  
Sludge Concentration

Electrochemical process is one of the most effective methods to enhance sludge disintegration. In this study, Ti/RuO2 anodes were prepared by Pechini’s method and the electrode surface morphology was characterized by FESEM and EDAX. The effects of various operating conditions were investigated including initial pH value of sludge, sludge concentration, electrolysis time and current density. The study showed that the removal efficiencies of TS, VS, TSS and VSS increased with the increase of pH in the alkaline range, electrolysis time and current density but decreased with the increase of initial sludge concentration. The application of electrochemical process using Ti/RuO2 electrodes enhanced the sludge disintegration for possible subsequent biological treatment.

scholarly journals Study on Anodic Oxidation parameters for removal of pesticide Imidacloprid on a modified tantalum surface by lead dioxide film

2020 ◽  
Keyword(s):  
Current Density ◽  
Crop Production ◽  
Ph Value ◽  
Lead Dioxide ◽  
Oxygen Demand ◽  
Electrochemical Process ◽  
Order Kinetic ◽  
Initial Ph ◽  
Transport Control ◽  
Dioxide Film

<p>The commercial imidacloprid (IMD) insecticide [1-(6-chloro-3-pyridinyl) methyl-4,5-dihydro-N-nitro-1H-imidazole-2-amine] is widely used for the enhancement of crop production, but the intensive use of this insecticide has caused serious environmental problems. This work presents an electrochemical process for the removal of this insecticide using galvanostatic electrolysis at modified tantalum surface by lead dioxide film anode (Ta(PbO2)) anode. The electrolytic process was monitored by chemical oxygen demand (COD). The influence of operating parameters, such as current density, initial concentration of IMD, temperature and initial pH value was investigated. The COD decay follows a pseudo first-order kinetic and the process was under mass transport control. COD removal reach 97% when using an apparent current density of 100 mA cm−2, initial COD of 953 mg L−1 and at 25 °C after 4.5 h electrolysis time.</p>

scholarly journals Electrochemical Degradation of Crystal Violet Using Ti/Pt/SnO2 Electrode

2021 ◽  
Vol 11 (18) ◽  
pp. 8401
Author(s):  
Rachid El Brychy ◽  
Mohamed Moutie Rguiti ◽  
Nadia Rhazzane ◽  
Moulay Driss Mellaoui ◽  
Khalid Abbiche ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Crystal Violet ◽  
Current Density ◽  
Ph Value ◽  
Supporting Electrolyte ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Initial Ph

Today, organic wastes (paints, pigments, etc.) are considered to be a major concern for the pollution of aqueous environments. Therefore, it is essential to find new methods to solve this problem. This research was conducted to study the use of electrochemical processes to remove organic pollutants (e.g., crystal violet (CV)) from aqueous solutions. The galvanostatic electrolysis of CV by the use of Ti/Pt/SnO2 anode, were conducted in an electrochemical cell with 100 mL of solution using Na2SO4 and NaCl as supporting electrolyte, the effect of the important electrochemical parameters: current density (20–60 mA cm−2), CV concentration (10–50 mg L−1), sodium chloride concentration (0.01–0.1 g L−1) and initial pH (2 to 10) on the efficiency of the electrochemical process was evaluated and optimized. The electrochemical treatment process of CV was monitored by the UV-visible spectrometry and the chemical oxygen demand (COD). After only 120 min, in a 0.01mol L−1 NaCl solution with a current density of 50 mA cm−2 and a pH value of 7 containing 10 mg L−1 CV, the CV removal efficiency can reach 100%, the COD removal efficiency is up to 80%. The process can therefore be considered as a suitable process for removing CV from coloured wastewater in the textile industries.

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.

Decolorization of Direct Yellow R Dye from Aqueous Solution by Aluminum Anode Electrochemical

2012 ◽  
Vol 581-582 ◽  
pp. 58-63
Author(s):  
Quang Phi Nguyen ◽  
Zhao Nan Sun ◽  
Xiao Min Hu
Keyword(s):  
Energy Consumption ◽  
Current Density ◽  
Ph Value ◽  
Dye Decolorization ◽  
Cell System ◽  
Impact Factors ◽  
Treatment Technique ◽  
Aluminum Anode ◽  
Initial Ph ◽  
Optimal Values

The present study applied Aluminum anode electrochemical method to decolorize direct yellow R wastewater. Experiments were conducted in electrochemical cell system with dimensions of 60 mm ´ 40 mm ´ 2 mm, a steel cathode and aluminum anode. Decolorization efficiency and electrical energy consumption were also calculated to compare optimal values. The effects of factors consist of current density, initial pH, initial dye concentration and electrolyte solution concentration on color removal efficiency have been also investigated. The results of study suggested that direct yellow R dye decolorization was very effective by using treatment technique applied in the study. The optimal values of impact factors were also indicated by. The initial dye concentration of 50 mg/l, initial pH value of 6.76, and current density of 2.5 mA/cm2 and Na2SO4 electrolyte concentration of 0.1mol/L were optimal conditions for dye decolorization. Besides that, the dye decolorization might reached the highest efficiency of 96.1% once it was conducted at temperature of 20°C, electrode distance of 16 mm and electrolyte time of 60 minutes. Energy consumption for decolorization in conditions mentioned above was 2.399 kWh/kg-dye.

scholarly journals Treatment of Zn2+ in wastewater by sinusoidal alternating current coagulation: response surface methodology and removal mechanism

2020 ◽  
Vol 82 (9) ◽  
pp. 1950-1960
Author(s):  
Yihui Zhou ◽  
Tao Xu ◽  
Jinhua Ou ◽  
Gege Zou ◽  
Xiping Lei ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Energy Consumption ◽  
Response Surface ◽  
Removal Efficiency ◽  
Current Density ◽  
Alternating Current ◽  
Initial Ph ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Main Component

Abstract A novel sinusoidal alternating current coagulation (SACC) technique was used to remove the Zn2+ from wastewater in the present study. The response surface methodology was used to analyze the effect of current density, time, initial pH and initial Zn2+ concentration in order to obtain the optimum removal efficiency and to lower energy consumption. The results show that SACC with a current density of 0.31 A·m−2 applied to treat wastewater containing 120 mg·dm−3 Zn2+ at pH = 9 for 21.3 min can achieve a removal efficiency of Zn2+ of 98.80%, and the energy consumption is 1.147 kWh·m−3. The main component of flocs produced in SACC process is Fe5O7OH·4H2O (HFO). Large specific surface area and good adsorption performance of HFO are demonstrated. There is strong interaction between Zn2+ and HFO. Zn2+ is adsorbed and trapped by HFO and then co-precipitated. Freundlich adsorption isotherm model and pseudo-second order kinetics model explained the Zn2+ adsorption behavior well. The Zn2+ adsorption on HFO is an endothermic and spontaneous process.

The Study on the Electrocatalytic Treatment of Dye Wastewater by ACF Cathode

2011 ◽  
Vol 356-360 ◽  
pp. 1386-1390
Author(s):  
Jun Sheng Hu ◽  
Yue Li ◽  
Hui Wang
Keyword(s):  
Current Density ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Strong Adsorption ◽  
Stainless Steel Cathode ◽  
Initial Ph ◽  
Operating Current ◽  
Alkaline Conditions ◽  
Acidic Conditions ◽  
Better Than

By using ACF as the cathode, acid scarlet 3R as simulated wastewater, the experiment researches into the effect of current density, aeration, electrolyte concentration and the initial pH value on the color removal of wastewater. The results showed that: ACF cathode has a strong adsorption capacity. Oxygen is reduced to H2O2 and other oxidizing substances H2O2 on the cathode surface .Therefore, it has a strong degradation capacity to dye, which is far better than that of the stainless steel cathode; Lower operating current density helps reduce processing costs; Higher electrolyte concentration and aeration is not necessarily better, which follows certain rules; The treatment is effected greatly by the initial pH, and the effect of decolonization in the acidic conditions is better than that in alkaline conditions. When the current density is 6Am/cm², electrolyte concentration is 0.04mol•L-1, aeration capacity is 0.2m3/h, initial pH is 3.5 and the time of treatment is 70min, the decolonization rate of wastewater is 95.30 %.

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%.

Decolorization of Crystal Violet by ultrasound/heterogeneous Fenton process

2013 ◽  
Vol 68 (11) ◽  
pp. 2515-2520 ◽  
Author(s):  
Hui Zhang ◽  
Hong Gao ◽  
Chun Cai ◽  
Chunyang Zhang ◽  
Lu Chen
Keyword(s):  
Crystal Violet ◽  
Ph Value ◽  
Catalyst Stability ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Heterogeneous Fenton ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Iron Leaching ◽  
Catalyst Dosage

Activated-carbon-supported iron oxides were prepared and used as a catalyst in an integrated ultrasound/heterogeneous Fenton process for the decolorization of Crystal Violet. A synergistic effect was observed when ultrasound was combined with the heterogeneous Fenton process. The decolorization efficiency increased with the increasing power density and catalyst dosage, but decreased with the increase of initial pH value. There exists an optimal hydrogen peroxide concentration for decolorization. Catalyst stability was evaluated by measuring iron leaching in solution. The decolorization efficiency was 88% under the optimal conditions. Toxicity test with Daphnia magna showed that the acute toxicity of dye solution decreased significantly after the treatment by the heterogeneous sono-Fenton process.

scholarly journals Removal of Trace Thallium from Industrial Wastewater by Fe0-Electrocoagulation

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 163 ◽  
Author(s):  
Xianghui Fu ◽  
Li Li ◽  
Guochao Yang ◽  
Xiangyang Xu ◽  
Lihua He ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Industrial Wastewater ◽  
Ph Value ◽  
Operation Time ◽  
Single Step ◽  
Toxic Heavy Metal ◽  
Effective Removal ◽  
Initial Ph ◽  
Effects Of Ph

As thallium (Tl) is a highly toxic heavy metal, there are compulsory environmental regulations in many countries on minimizing its release. This research investigated the treatment of real industrial wastewater with low Tl(I) concentration by Fe0-electrocoagulation (Fe0-EC) in a batch aeration-forced pump cycle reactor. The effects of pH (7–12), current density (8.3–33.3 mA/cm2), dissolved oxygen (DO) in wastewater, and initial Tl(I) concentration (66–165 µg/L) on Tl(I) removal efficiency were investigated. The removal efficiency of Tl(I) is pH-dependent, to be exact, it increases significantly with pH rising from 8 to 11. Initial pH of influent and DO concentration were the key operation parameters which strongly affect Tl(I) removal. After the water sample with initial Tl(I) concentration of 115 µg/L was treated for 12 min by a single-step process at pH of 11 and current density of 16.7 mA/cm2, the residual Tl(I) concentration was decreased to beneath the emission limit in China (2 µg/L) with a low energy consumption of 0.82 kWh/m3. By prolonging the operation time, the concentration was further reduced to 0.5 µg/L or even lower. The main composition of the flocculent sludges is iron oxyhydroxide, yet its crystal structure varies dependent on pH value which may result in different Tl(I) removal efficiency. Feroxyhyte nanosheets generate in situ by Fe0-EC, which contributes to the rapid and effective removal of Tl(I), while the speedy oxidation under DO-enriched conditions benefits the feroxyhyte formation. The mechanism of Tl(I) removal by Fe0-EC is attributed to the combination of electrostatic attraction and the formation of inner-sphere complexes. As shown in the technical and mechanical studies, Fe0-EC technology is an effective method for low Tl concentration removal from wastewater.

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