Effect of alternating and direct current in an electrocoagulation process on the removal of cadmium from water

2012 ◽  
Vol 65 (2) ◽  
pp. 353-360 ◽  
Author(s):  
S. Vasudevan ◽  
J. Lakshmi
Keyword(s):  
Energy Consumption ◽  
Removal Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Adsorption Process ◽  
Second Order ◽  
Operating Parameters ◽  
Electrocoagulation Process ◽  
A Current

The main objective of this study was to investigate the effects of AC and DC on the removal of cadmium from water using iron as anode and cathode. The various operating parameters on the removal efficiency of cadmium were investigated. The results showed that the optimum removal efficiency of 98.1 and 97.3% with the energy consumption of 0.734 and 1.413 kWh/kL was achieved at a current density of 0.2 A/dm2, at pH of 7.0 using AC and DC respectively. The adsorption process follows second order kinetics and the temperature studies showed that adsorption was endothermic and spontaneous in nature.

scholarly journals Copper and Lead Ions Removal by Electrocoagulation: Process Performance and Implications for Energy Consumption

2021 ◽  
Vol 10 (3) ◽  
pp. 415-424
Author(s):  
Aji Prasetyaningrum ◽  
Dessy Ariyanti ◽  
Widayat Widayat ◽  
Bakti Jos
Keyword(s):  
Heavy Metals ◽  
Energy Consumption ◽  
Removal Efficiency ◽  
Current Density ◽  
High Current Density ◽  
Energy Requirement ◽  
Lead Ions ◽  
Initial Concentration ◽  
Electroplating Wastewater ◽  
Electrocoagulation Process

Electroplating wastewater contains high amount of heavy metals that can cause serious problems to humans and the environment. Therefore, it is necessary to remove heavy metals from electroplating wastewater. The aim of this research was to examine the electrocoagulation (EC) process for removing the copper (Cu) and lead (Pb) ions from wastewater using aluminum electrodes. It also analyzes the removal efficiency and energy requirement rate of the EC method for heavy metals removal from wastewater. Regarding this matter, the operational parameters of the EC process were varied, including time (20−40 min), current density (40−80 A/m2), pH (3−11), and initial concentration of heavy metals. The concentration of heavy metals ions was analyzed using the atomic absorption spectroscopy (AAS) method. The results showed that the concentration of lead and copper ions decreased with the increase in EC time. The current density was observed as a notable parameter. High current density has an effect on increasing energy consumption. On the other hand, the performance of the electrocoagulation process decreased at low pH. The higher initial concentration of heavy metals resulted in higher removal efficiency than the lower concentration. The removal efficiency of copper and lead ions was 89.88% and 98.76%, respectively, at 40 min with electrocoagulation treatment of 80 A/m2 current density and pH 9. At this condition, the specific amounts of dissolved electrodes were 0.2201 kg/m3, and the energy consumption was 21.6 kWh/m3. The kinetic study showed that the removal of the ions follows the first-order model.

scholarly journals Removal of Methylene Blue in aqueous solutions by Electrocoagulation process: Adsorption, Kinetics, studies

2018 ◽  
Vol 9 (4) ◽  
pp. 311-316 ◽  
Author(s):  
Alain Stéphane Assémian ◽  
Konan Edmond Kouassi ◽  
Kopoin Adouby ◽  
Patrick Drogui ◽  
David Boa
Keyword(s):  
Methylene Blue ◽  
Energy Consumption ◽  
Adsorption Kinetics ◽  
Current Density ◽  
Goodness Of Fit ◽  
Specific Energy Consumption ◽  
Second Order ◽  
Rate Equations ◽  
Order Kinetic ◽  
Electrocoagulation Process

The purpose of this study is to understand the mechanism driving the removal of methylene blue through electrocoagulation process. Experiments were carried out using iron as anode and cathode in a batch electrochemical cell operated in a monopolar configuration. The effects of operating parameters (initial pH, current density, initial dye concentration and energy consumption) on the removal of methylene blue from solution were investigated. The results showed that the optimum removal efficiency of 93.2% was achieved for a current density of 9.66 mA/cm2, optimal pH of 8±0.01 with a specific energy consumption of 7.451 kWh/m3. Afterwards, first and second-order rate equations were successively applied to study adsorption kinetics models. On top of usual correlation coefficients (r2), statistical test Chi-square (χ2) were applied to evaluate goodness of fit and consequently find out the best kinetic model. Results showed that MB adsorption process onto iron hydroxides formed in aqueous solution during electrocoagulation treatment followed a second-order kinetic.

scholarly journals Electrochemical oxidation as a post treatment for biologically tannery wastewater in batch reactor

2019 ◽  
Vol 80 (7) ◽  
pp. 1326-1337 ◽  
Author(s):  
Tran Le Luu ◽  
Djeuga Djeuga Franck Stephane ◽  
Nguyen Hoang Minh ◽  
Nguyen Duc Canh ◽  
Bui Xuan Thanh
Keyword(s):  
Energy Consumption ◽  
Electrochemical Oxidation ◽  
Organic Compounds ◽  
Current Density ◽  
Batch Reactor ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Tannery Wastewater ◽  
Stirring Rate ◽  
A Current

Abstract Tannery wastewater is known to contain high concentrations of organic compounds, heavy metals, nitrogen, sulphur, chromium, and many other chemicals. Both aerobic and anaerobic biological approaches have proven ineffective in the treatment of tannery wastewater due to the high salinity and toxic chemicals contained within the medium. Electrochemical oxidation presents a promising method for solving this problem. High pollutant removal efficiency, low energy consumption, and high electrode stability are three important factors supporting the feasibility of an efficient electrochemical treatment process. In the present study, electrochemical oxidation was performed as a post treatment for tannery wastewater (after biological pre-treatment) in a batch reactor using Ti/RuO2, Ti/IrO2, and Ti/BDD anodes. The effects of pH, current density, stirring rate and treatment time were studied to assess the treatment efficiency as well as the energy consumption of the process. The results showed that colour, chemical oxygen demand (COD), total organic carbon (TOC), and total nitrogen (TN) removal efficiencies on the electrodes were: Ti/RuO2 (88.8%, 88.40%, 64.0%, 96.4%), Ti/IrO2 (85.40%, 85.9%, 52.3%, 51.4%), Ti/BDD (90.60%, 94.7%, 90.5%, 82.7%) respectively, at a current density of 80 mA/cm2. All three electrodes demonstrated optimal performance at a pH of 8, a stirring rate of 400 rpm, a current density of 80 mA/cm2, and an electrolysis time of 5 h. The concentration of tri-chloromethane by-product was detected with limiting value. Electrochemical oxidation thus offers a feasible method for removing organic compounds and nutrients from tannery wastewater.

Removal of Cadmium from Red Soil by Electrokinetic Method

2012 ◽  
Vol 518-523 ◽  
pp. 3061-3064
Author(s):  
Chun Fang Tang ◽  
Xiao Fang Zhou ◽  
Cheng Feng Li
Keyword(s):  
Energy Expenditure ◽  
Laboratory Experiment ◽  
Removal Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Promising Technology ◽  
Red Soils ◽  
Electrokinetic Method ◽  
Ph Dependent ◽  
The Cost

A constant direct current density of 0.5 mA/cm2was applied in a laboratory experiment for studing the feasibility of electrokinetic treatment on the removal of Cd from red soils. The result shows that the removal efficiency of Cd was remarkably pH-dependent. The initial Cd concentration was1490 mg/kg and over 79% of Cd was removed from the red soils after 96 hours’ treatment. The energy expenditure was about 77.6 kW.h/m3and the cost was 42.6 RMB Yuan/m3, which suggest that electrokinetic soil processing is a promising technology for remedying cd-contaminated red soils.

scholarly journals Removal Efficiency of Acid Red 18 Dye from Aqueous Solution Using Different Aluminium-Based Electrode Materials by Electrocoagulation Process

2020 ◽  
Vol 20 (3) ◽  
pp. 536
Author(s):  
Nurulhuda Amri ◽  
Ahmad Zuhairi Abdullah ◽  
Suzylawati Ismail
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Electrode Materials ◽  
Cost Effective ◽  
Aluminium Electrode ◽  
Electrocoagulation Process ◽  
Commercial Aluminium ◽  
A Current ◽  
Better Than

This work compares commercial aluminium electrode for use in the treatment of wastewater by electrocoagulation process against waste aluminium cans electrode. The applicability of the waste aluminium cans electrode was tested for decolorization of Acid Red 18 dye as a model pollutant. The batch electrocoagulation process using both types of electrode was conducted at a current density of 25 mA/cm2, a pH of 3, an initial concentration of 100 mg/L and 25 min of reaction time. The elemental composition and surface morphology of both electrode materials and the sludge produced were analyzed using SEM-EDX to establish the correlation between the properties and characteristics of both electrode materials with their dye removal performance. The results demonstrated that waste aluminium cans performed better than commercial aluminium electrode with a removal efficiency of 100% in 25 min of reaction time. This was due to the higher Al dissolution of waste aluminium cans electrode that contributed to the larger amount of Al3+ released into the solution to consequently form more flocs to remove the dye molecules. In conclusion, the proposed waste aluminium electrode was considered as efficient and cost-effective and had the potential to replace the conventional ones in treating colored industrial wastewater using electrocoagulation process.

scholarly journals Removal of Cadmium from Industrial Wastewater using Electrocoagulation Process

2019 ◽  
Vol 26 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Mohammed Alameen Salem ◽  
Najwa Majeed
Keyword(s):  
Heavy Metal ◽  
Removal Efficiency ◽  
Applied Voltage ◽  
Industrial Wastewater ◽  
Batch Reactor ◽  
Operating Parameters ◽  
Initial Concentration ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Aluminum Electrodes

Cadmium is one of the heavy metal found in the wastewater of many industries. The electrocoagulation offers many advantages for the removal of cadmium over other methods. So the removal of cadmium from wastewater by using electrocoagulation was studied to investigate the effect of operating parameters on the removal efficiency. The studied parameters were the initial pH, initial concentration, and applied voltage. The study experiments were conducted in a batch reactor with  with two pairs of aluminum electrodes with dimension  and 2mm in thick with 1.5 cm space between them. The optimum removal was obtained at pH =7, initial concentration = 50 mg/L, and applied voltage = 20 V and it was 90%.

scholarly journals The Effect of Brush Plate Structure and Operating Parameters on the Energy Consumption of Electrolytic Cells

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2186
Author(s):  
Shengxian Yi ◽  
Zhongjiong Yang ◽  
Liqiang Zhou ◽  
Gaofeng Zhang
Keyword(s):  
Energy Consumption ◽  
Density Distribution ◽  
Current Density ◽  
Current Density Distribution ◽  
Electrolytic Cell ◽  
Anode Surface ◽  
Operating Parameters ◽  
Additional Energy ◽  
Impact Time ◽  
The Impact

The nickel powder brush plate is a core component of the direct contact between the cleaning machine and cathode plate of an electrolyzer, and its movement in the electrolytic cell will affect the energy consumption of the electrolyzer. In order to optimize the structure of the brush plate, a cleaning trolley brush plate was taken as the research object, a mathematical model of its electrolyzer was established, and the reliability was subsequently verified. The influence of the structural and operating parameters of the brush plate on the energy consumption of the electrolytic cell was studied. The research results show that additional energy consumption is the lowest in the process of cleaning a return grooved brush plate. Brush plates with a large slotting area have less impact on the energy consumption of the electrolyzer. The slotting method, where the anodes are arranged directly opposite each other and relatively concentrated, can be adapted to render a more uniform current density distribution on the anode surface, with lower energy consumption and less variation in voltage and current. With the increasing number of slots from one to three, the current density distribution on the anode surface became more uniform, with a reduction in the variation range of the slot voltage and current in the branch where the cathode plate was cleaned and a decreased energy consumption. With the linear increase in brush cleaning speed, the impact time of the brush plate on the electrolyzer decreased nonlinearly, and as the extent of this decrease gradually diminished, the additional energy consumption showed the same trend. These research results were then used as a basis for optimizing the existing commonly used empirical C-brush plates. Following optimization, the current density distribution on the anode surface was found to be more uniform, the variation amplitude of tank voltage was reduced by 34%, the current drop amplitude of the branch circuit where the brushed cathode plate was located was reduced by 39%, the impact time on the current field of the electrolytic tank was reduced by 40%, and the additional energy consumption was reduced by 50.9%. These results can be served as a reference for further theoretical research related to brush plates.

Removing of the Dye Pollutant Acid Red 1 from Contaminated Waters by Electrocoagulation Method Using a Recirculating Tubular Reactor with Punched Anode

2019 ◽  
Vol 41 (1) ◽  
pp. 191-191
Author(s):  
Mohsen Garajehdaghi and Kambiz Seyyedi Mohsen Garajehdaghi and Kambiz Seyyedi
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Tubular Reactor ◽  
Electrolysis Time ◽  
Electrocoagulation Process ◽  
Acid Red 1 ◽  
Contaminated Waters

In the present study the removal of Acid red 1 (AR1), as a pollutant of contaminated waters, was investigated by the electrocoagulation method using a recirculating tubular reactor with punched anode. The role of the parameters affecting removal efficiency including current density, electrolysis time, electrolyte concentration and type, pH, the flow rate of the solution, and dye concentration was studied. Spectrophotometric results indicated that for 2500 ml of the dye solution containing 30 mg L-1 AR1 more than 95% of the dye was removed under the following conditions: current density of 1.3 mA cm-2, electrolysis time of 20 min, pH of 6, electrolyte dosage of 0/08 g L-1 , and the flow rate of 2 L min-1. Results showed that with an increase the electrolyte concentration and current density, color removal efficiency increases. Increasing of the flow rate of solution in the reactor due to decrease the retention time, decreases the removal efficiency. According to nature of electrocoagulation process, neutral range of pH is suitable for decolorization process.

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.

scholarly journals Adsorption of Organic Pollutants from Cold Meat Industry Wastewater by Electrochemical Coagulation: Application of Artificial Neural Networks

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3040
Author(s):  
Jorge del Real-Olvera ◽  
Juan Morales-Rivera ◽  
Ana Patricia González-López ◽  
Belkis Sulbarán-Rangel ◽  
Virgilio Zúñiga-Grajeda
Keyword(s):  
Organic Pollutants ◽  
Current Density ◽  
Adsorption Process ◽  
Second Order ◽  
Experimental Results ◽  
Maximum Adsorption Capacity ◽  
Meat Industry ◽  
Initial Ph ◽  
Artificial Neural ◽  
Industry Wastewater

The cold meat industry is considered to be one of the main sources of organic pollutants in the wastewater of the meat sector due to the complex mixture of protein, fats, and dyes present. This study describes electrochemical coagulation (EC) treatment for the adsorption of organic pollutants reported in cold meat industry wastewater, and an artificial neural network (ANN) was employed to model the adsorption of chemical oxygen demand (COD). To depict the adsorption process, the parameters analyzed were current density (2–6 mA cm−2), initial pH (5–9), temperature (288–308 K), and EC time (0–180 min). The experimental results were fit to the Langmuir and Freundlich isotherm equations, while the modeling of the adsorption kinetics was evaluated by means of pseudo-first and pseudo-second-order rate laws. The data reveal that current density is the main control parameter in EC treatment, and 60 min are required for an effective adsorption process. The maximum removal of COD was 2875 mg L−1 (82%) when the following conditions were employed: pH = 7, current density = 6 mA cm−2, and temperature of 298 K. Experimental results obey second-order kinetics with values of the constant in the range of 1.176 × 10−5 ≤ k2 (mg COD adsorbed/g-Al.min) ≤ 1.284 × 10−5. The ANN applied in this research established that better COD removal, 3262.70 mg L−1 (93.22%) with R2 = 0.98, was found using the following conditions: EC time of 30.22 min, initial pH = 7.80, and current density = 6 mA cm−2. The maximum adsorption capacity of 621.11 mg g−1 indicates a notable affinity between the organic pollutants and coagulant metallic ions.

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