scholarly journals A novel gradient current density output mode for effective electrochemical oxidative degradation of dye wastewater by boron-doped diamond (BDD) anode

2020 ◽  
Vol 82 (10) ◽  
pp. 2085-2097
Author(s):  
Ting Liu ◽  
Dongtian Miao ◽  
Guoshuai Liu ◽  
Qiuping Wei ◽  
Kechao Zhou ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Current Density ◽  
High Energy ◽  
Molecular Structures ◽  
Constant Current ◽  
Dye Wastewater ◽  
Output Process ◽  
Boron Doped Diamond ◽  
General Applicability

Abstract In order to solve the problems of high energy consumption and low current efficiency in electrochemical oxidation (EO) degradation under the traditional constant output process (COP), a gradient output process (GOP) of current density is proposed in this paper. That is, the current density is gradually reduced in a fixed degradation time, and the Reactive Blue 19 simulated dye wastewater was used as the degradation target. The general applicability of the process was further confirmed by studying the optimal gradient current density output parameters, the dye concentration, electrolyte concentration and other dye compounds with different molecular structures. The corresponding results show that the chemical oxygen demand (COD) removal (78%) and the color removal (100%) under the GOP are similar to those in the COP, and the overall energy consumption is reduced by about 50% compared with that in the traditional constant current mode. Moreover, the current efficiency in the middle and late stages of EO process has increased by 8.6 times compared with COP.

scholarly journals INVESTIGATION OF ELECTROCHEMICAL COLOR REMOVAL FROM ORGANIZED INDUSTRIAL DISTRICT (OID) WASTEWATER TREATMENT PLANTS USING NEW GENERATION Sn/Sb/Ni-Ti ANODES

2018 ◽  
Vol 21 (2) ◽  
pp. 106-112
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Current Density ◽  
Wastewater Treatment Plants ◽  
Salt Content ◽  
Color Removal ◽  
Ozone Production ◽  
Ambient Conditions ◽  
Operational Parameters ◽  
Oxidation Efficiency

<p>In this study, the application of Sn/Sb/Ni-Ti electrodes for the treatment of waste streams were investigated which is promising for ozone production by electrolysis of water because of their stability and high potential for ozone evolution reaction. These series of anodes have a high electrochemical ozone generation potential at ambient conditions (approximately up to 40% current efficiency). But using and testing of these novel anodes for real wastewater are too limited in the literature. Titanium mesh substrate coated with Sn/Sb/Ni-Ti alloy was used as anode immersed in wastewater at room temperature with platinized titanium cathode. These electrodes used for COD and color removal from OID wastewater in Inegol, Bursa, Turkey. Five operational parameters were evaluated for electrochemical COD and color removal processes, such as pH, salt content, applied voltage/current, current efficiency and contact time. Experimental results showed that after 30 min the electrochemical oxidation efficiency of COD and color could reach up to 98% and 99% respectively at pH 8.2 and temperature of 25°C as the optimum conditions. Current density observed as the most effective parameter for COD and color removal efficiencies. The lowest energy consumption was between 10-25 mA cm-2 of current density with only 0.6 kWh gCOD−1, while the highest energy consumption was 100 mA cm-2 of current density with 9.12 kWh gCOD−1 . The optimum current density value has been found as 50 mA cm-2 with 4.05 kWh gCOD−1 . These results were also supported with ANOVA test.</p>

scholarly journals Selective Recovery of Tellurium from the Tellurium-Bearing Sodium Carbonate Slag by Sodium Sulfide Leaching Followed by Cyclone Electrowinning

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1176
Author(s):  
Zhipeng Xu ◽  
Zoujiang Li ◽  
Dong Li ◽  
Xueyi Guo ◽  
Ying Yang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Sodium Carbonate ◽  
Flow Rate ◽  
Current Density ◽  
Sodium Sulfide ◽  
Cell Voltage ◽  
Promising Alternative ◽  
Selective Recovery ◽  
Solid Ratio

The rigorous environmental requirements promote the development of new processes with short and clean technical routes for recycling tellurium from tellurium-bearing sodium carbonate slag. In this paper, a novel process for selective recovery of tellurium from the sodium carbonate slag by sodium sulfide leaching, followed by cyclone electrowinning, was proposed. 88% of tellurium was selectively extracted in 40 g/L Na2S solution at 50 °C for 60 min with a liquid to solid ratio of 8:1 mL/g, while antimony, lead and bismuth were enriched in the leaching residue. Tellurium in the leach liquor was efficiently electrodeposited by cyclone electrowinning without purification. The effects of current density, temperature and flow rate of the electrolyte on current efficiency, tellurium recovery, cell voltage, energy consumption, surface morphology, and crystallographic orientations were systematically investigated. 91.81% of current efficiency and 95.47% of tellurium recovery were achieved at current density of 80 A/m2, electrolyte temperature of 45 °C and electrolyte flow rate of 400 L/h. The energy consumption was as low as 1.81 kWh/kg. A total of 99.38% purity of compact tellurium deposits were obtained. Therefore, the proposed process may serve as a promising alternative for recovering tellurium from tellurium-bearing sodium carbonate slag.

scholarly journals Electrooxidation of Diclofenac in Synthetic Pharmaceutical Wastewater Using an Electrochemical Reactor Equipped with a Boron Doped Diamond Electrode

2017 ◽  
Vol 58 (3) ◽  
Author(s):  
Gabriela Coria ◽  
José L. Nava ◽  
Gilberto Carreño
Keyword(s):  
Energy Consumption ◽  
Current Density ◽  
Electrochemical Reactor ◽  
Pharmaceutical Wastewater ◽  
Boron Doped Diamond ◽  
Linear Flow ◽  
Diamond Electrode ◽  
Boron Doped ◽  
Boron Doped Diamond Electrode ◽  
Set Up

This paper deals with the degradation of diclofenac by electrochemical oxidation in NaClO<sub>4</sub> medium at neutral pH using a FM01-LC reactor equipped with a boron doped diamond electrode (BDD). Microelectrolysis studies were carried out to find the current density domain where hydroxyl radical (<sup>•</sup>OH) formation is favored, 10 ≤ j ≤ 20 mA cm<sup>-2</sup>. Electrolysis experiments at mean linear flow velocities of 14.6 ≤ u ≤ 58.4 cm s<sup>-1</sup> were performed. The experimental set-up achieved 100% diclofenac mineralization with 78% current efficiency and energy consumption of 2.54 kWh m<sup>-3</sup> at j = 15 mA cm<sup>-2</sup> and u=29.2 cm s<sup>-1</sup>.

scholarly journals High-Throughput Computational Screening of Ionic Liquids for Butadiene and Butene Separation

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 165
Author(s):  
Hao Qin ◽  
Zihao Wang ◽  
Zhen Song ◽  
Xiang Zhang ◽  
Teng Zhou
Keyword(s):  
Ionic Liquids ◽  
Energy Consumption ◽  
High Throughput ◽  
Physical Property ◽  
Extractive Distillation ◽  
High Energy ◽  
Molecular Structures ◽  
Boiling Points ◽  
Computational Screening ◽  
Potential Alternative

The separation of 1,3-butadiene (1,3-C4H6) and 1-butene (n-C4H8) is quite challenging due to their close boiling points and similar molecular structures. Extractive distillation (ED) is widely regarded as a promising approach for such a separation task. For ED processes, the selection of suitable entrainer is of central importance. Traditional ED processes using organic solvents suffer from high energy consumption. To tackle this issue, the utilization of ionic liquids (ILs) can serve as a potential alternative. In this work, a high-throughput computational screening of ILs is performed to find proper entrainers, where 36,260 IL candidates comprising of 370 cations and 98 anions are involved. COSMO-RS is employed to calculate the infinite dilution extractive capacity and selectivity of the 36,260 ILs. In doing so, the ILs that satisfy the prespecified thermodynamic criteria and physical property constraints are identified. After the screening, the resulting IL candidates are sent for rigorous process simulation and design. 1,2,3,4,5-pentamethylimidazolium methylcarbonate is found to be the optimal IL solvent. Compared with the benchmark ED process where the organic solvent N-methyl-2-pyrrolidone is adopted, the energy consumption is reduced by 26%. As a result, this work offers a new IL-based ED process for efficient 1,3-C4H6 production.

Current Efficiency and Energy Consumption of Electrochemical Oxidation for Ammonia Removal from Coking Wastewater Using Boron-Doped Diamond Electrodes

2013 ◽  
Vol 295-298 ◽  
pp. 1327-1332 ◽  
Author(s):  
Chun Rong Wang ◽  
Sha Chang ◽  
Min Ye ◽  
Qin Yi Ren
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Current Density ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Ammonia Removal ◽  
Ion Concentration ◽  
Coking Wastewater ◽  
Concentration Increase ◽  
Density Decrease

The electrochemical treatment of ammonia using born-doped diamond (BDD) as advanced treatment of coking wastewater was investigated. The effects of chloride ion concentration and current density on current efficiency and energy consumption were also analyzed. The results show that the current efficiency increases with chloride ion concentration increase and current density decrease. And 30% of current efficiency is obtained when current density is less than 19.7mA cm-2, and it decreases above 19.7mA cm-2. The energy consumption decreases with the chloride ion concentration increase and current density decrease. And energy consumption of 0.50kWh g-1 and ammonia removal rate of 84.7% can be achieved at initial ammonia concentration of 100mg L-1, chloride concentration of 900mg L-1 and current density of 29.6mA cm-2.Therefore, BDD electrodes have high current efficiency and low energy consumption, which attributed to its high oxygen evolution overvoltage (2.6V vs. SCE) and low chloride evolution overvoltage (1.5V vs. SCE).

Electro-Crystallization of Antimony from Acidic and Alkaline Baths in Diaphragm-Less Cell

2013 ◽  
Vol 828 ◽  
pp. 65-72 ◽  
Author(s):  
Chinmaya Kumar Sarangi ◽  
Ayonbala Baral ◽  
Jayasmita Panigrahi ◽  
Kali Sanjay ◽  
Tondepu Subbaiah ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Current Density ◽  
Cathodic Current ◽  
Antimony Concentration ◽  
Morphological Studies ◽  
Alkaline Bath ◽  
Alkaline Baths ◽  
Acidic Bath

Studies based on electrocrystallization of antimony were carried out to evaluate the effects of current density and antimony concentration in the electrolytic bath on cathodic current efficiency, energy consumption, and quality of the deposits during electrowinning of antimony from Sb2O3-HCl and Sb2S3-NaOH systems. In acidic bath, current efficiency for electrodeposition of antimony increases with the increase in current density till 150 A/m2, beyond which it follows a trend of gradual diminution. On varying antimony concentration in the bath, current efficiency was found to improve significantly and the optimum antimony concentration in Sb2O3-HCl system was evaluated to be about 60 g/L. In alkaline bath, current efficiency was observed to be maximum at 50 A/m2and further, with the increase in current density it progressively decreases. However, energy consumption for electrowinning of antimony in both of the baths gradually increases with the increase in current density. At a current density less than 150 A/m2, alkaline bath was found to be more current efficient in comparison to the acidic bath. Crystallographic studies by XRD, imaging by optical microscopic technique and morphological studies by SEM were also carried out to differentiate antimony deposits obtained from acidic and alkaline baths.

scholarly journals Optimization of raw acrylic yarn dye wastewater treatment by electrochemical processes: kinetic study and energy consumption

2019 ◽  
Keyword(s):  
Energy Consumption ◽  
Current Density ◽  
Removal Rate ◽  
Kinetic Modelling ◽  
Dye Wastewater ◽  
Colour Removal ◽  
Important Place ◽  
Toc Removal ◽  
Initial Ph ◽  
Electrocoagulation Process

<p>The textile industry has an important place in the environmental pollution due to its heavy water consumption and to the toxic content of dye. Every succeeding day, the water quality is deteriorated because the wastewater containing the dye is supplied to the receiving medium. In this study, The electrocoagulation and electrofenton processes, which produce less waste than the conventional methods and which are less costly, have been investigated for decolourization of acrylic yarn dyeing wastewater. The electrocoagulation process was involved four electrodes parallel connected. To optimize the treatment, response surface methodology (RSM) was applied. The operating independent conditions were selected as the current density (20 -100 A/m2), reaction time (5-25 minutes) and initial pH (pH 4.3-pH 8.3). As a result of optimization by RSM method, the highest Colour, COD and TOC removal were obtained as 96.2%, 43.8% and 40.4 % , respectively. In order to obtain these results, it was necessary to apply a current density of 100 A/m2 to the wastewater which has been set to an initial pH of 7.2 and 20.7 minutes. With the experimental setup installed, high colour removal can be achieved in as little as 15 minutes. Although the colour removal is high, COD removal does not meet discharge standards. Therefore, electrofenton process was applied for enhancing COD and TOC removal and removal rate increased to 70.0% and 61.5%, respectively. In order to study the removal mechanism for acrylic yarn dye wastewater by electrocoagulation process, kinetic modelling was applied. Energy consumption was also assessed.</p>

Recovery of Heavy Metal from Scrap Metal Pickling Wastewater by Electrolysis

1993 ◽  
Vol 28 (7) ◽  
pp. 223-229 ◽  
Author(s):  
Ju-Sheng Huang ◽  
I-Chung Lee ◽  
Biing-Jauh Lin
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Deposition Rate ◽  
Current Density ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Copper Ion ◽  
Surface Loading ◽  
Electro Deposition ◽  
Continuous Flow Reactors

When the influent surface loading of copper ion in the four-stage continuous-flow reactors of electrolysis were controlled at 143.9, 94.0, 52.7 and 33.2 mg/min-dm2, respectively, and current density were controlled at 3.9, 2.6, 1.3 and 1.3A/dm2, respectively, the concentration of copper decreased from 13,900 to l,900mg/l (i.e., the electro-deposition rate of copper were 2,700, 2,240, 1,500 and 750 mg/dm2-h, respectively). The purity of copper depositing on the cathode reached over 98%. When the current density was ranged from 1.3 to 3.9A/dm2, the electro-deposition rate of copper increased with the increasing current density. However, when the current density was raised above 5.2 A/dm2, the electro-deposition rate of copper decreased with the increasing current density. The increase of current density decreased the current efficiency and increased the specific energy consumption. The increase of influent surface loading of copper ion increased the current efficiency and decreased the specific energy consumption.

Enhanced Ion Transport in an Ether Aided Super Concentrated Ionic Liquid Electrolyte for Long-Life Practical Lithium Metal Battery Applications

2020 ◽  
Author(s):  
Urbi Pal ◽  
Fangfang Chen ◽  
Derick Gyabang ◽  
Thushan Pathirana ◽  
Binayak Roy ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ion Transport ◽  
Current Density ◽  
Coulombic Efficiency ◽  
High Energy ◽  
Liquid Electrolyte ◽  
High Mass ◽  
Lithium Metal ◽  
Ionic Liquid Electrolyte ◽  
Lithium Metal Battery

We explore a novel ether aided superconcentrated ionic liquid electrolyte; a combination of ionic liquid, <i>N</i>-propyl-<i>N</i>-methylpyrrolidinium bis(fluorosulfonyl)imide (C<sub>3</sub>mpyrFSI) and ether solvent, <i>1,2</i> dimethoxy ethane (DME) with 3.2 mol/kg LiFSI salt, which offers an alternative ion-transport mechanism and improves the overall fluidity of the electrolyte. The molecular dynamics (MD) study reveals that the coordination environment of lithium in the ether aided ionic liquid system offers a coexistence of both the ether DME and FSI anion simultaneously and the absence of ‘free’, uncoordinated DME solvent. These structures lead to very fast kinetics and improved current density for lithium deposition-dissolution processes. Hence the electrolyte is used in a lithium metal battery against a high mass loading (~12 mg/cm<sup>2</sup>) LFP cathode which was cycled at a relatively high current rate of 1mA/cm<sup>2</sup> for 350 cycles without capacity fading and offered an overall coulombic efficiency of >99.8 %. Additionally, the rate performance demonstrated that this electrolyte is capable of passing current density as high as 7mA/cm<sup>2</sup> without any electrolytic decomposition and offers a superior capacity retention. We have also demonstrated an ‘anode free’ LFP-Cu cell which was cycled over 50 cycles and achieved an average coulombic efficiency of 98.74%. The coordination chemistry and (electro)chemical understanding as well as the excellent cycling stability collectively leads toward a breakthrough in realizing the practical applicability of this ether aided ionic liquid electrolytes in lithium metal battery applications, while delivering high energy density in a prototype cell.

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