جستجوی مقالات مرتبط با کلیدواژه « electrocoagulation » در نشریات گروه « شیمی »

Electrocoagulation has demonstrated its efficacy in treating industrial effluents by effectively removing pollutants, particularly metallic contaminants. The electrochemical processes occurring at aluminum electrodes have shown excellent performance in this regard. In this study, electrocoagulation experiments were conducted on an industrial effluent originating from an electroplating bath situated in Casablanca, Morocco. The primary objective was to eliminate chromium in the effluent and reuse the processed water for other applications within our  facility. To achieve this goal, we systematically optimized various operational parameters influencing the electrocoagulation efficiency, including electrical voltage, electrode material, stirring speed, and electrode spacing. Additionally, we assessed their impact on pH, conductivity, and chromium concentration. The experiments were conducted in a well-mixed reactor using an industrial solution containing a high concentration of chromium, specifically 1 g/l of Cr (VI). The chromium removal efficiency was evaluated under specific operational conditions, including the use of aluminum electrodes, regulated voltages of 6 volts and 12 volts, an optimal stirring speed of 600 rpm, and an electrode spacing of 2 cm.

This study focuses on evaluating the electrocoagulation process as a method for the treatment of real municipal wastewater using aluminum plate electrodes as an anode in a batch electrochemical reactor. An attempt was made to model the Chemical Oxygen Demand (COD) removal and Electrical Energy Consumption (EEC) as a function of the critical operating variables for the determination of optimal conditions statistically. The initial pH, current, and reaction time were selected as key independent variables in a five-level Central Composite Design (CCD); at the same time,  COD removal efficiency and EEC were considered as the response function. At the optimum conditions proposed by CCD (pH=6.2, I=0.025A, and T=46 min), a maximum COD removal efficiency of 85.7% with electrical energy consumption of 0.151 kW h/m3 was achieved. In addition, the operating costs, energy; and electrode consumptions at optimum conditions were calculated to be 0.1127079 $/m3, 0.151 kWh/m3; and 0.026 kg/m3, respectively. These results presented here prove that the EC process has good performance and great potential for efficient treatment of real municipal wastewater.

This study aims to compare the effectiveness of ElectroCoagulation (EC) and Electro-Fenton (EF) processes in the treatment of high-strength storage leachate. The effect of operating parameters, including initial pH, contact time, and mass ratio of COD: H2O2, on Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies of leachate was investigated. For this purpose, a jacketed reactor in which the electrochemical process is performed using monopolar-bonded iron electrodes is designed. As a result of the experimental studies, the optimum operating parameters of the EC process were determined as follows: pH 7, current density 150A/m2, and reaction time 30 minutes. Under these conditions, 37.87% COD and 47.36% TOC were removed respectively. Due to the lack of expected results in the treatment of this wastewater in the EC process, treatability studies were carried out with the EF process. As a result of the study, optimum conditions were found to be pH 3, current density 150 A/m2, H2O2= 500 mg/L (KOI: H2O2@1), and working time 10 min. A higher COD (71.7%) and TOC removal (90.87%) have been obtained with the EF process under optimum conditions. The operating costs of electrocoagulation and electro-Fenton processes under optimum conditions were calculated as 2.26 and 1.78 €/m3, respectively. Experimental findings revealed that, unlike the EC process, the EF process can be a good option for landfill leachate treatment in terms of providing less treatment time, less sludge, more cost-effectiveness, and necessary discharge limits.

The widespread use of aluminum-based food packaging materials has significantly contributed to an increase in aluminum waste generation, the majority of which ends up in landfills. To address this issue, the current study attempted to recycle Waste Aluminum Cans (WAC) by converting them into an effective electrode for the treatment of Acid Red 18 (AR18) dye via electrocoagulation (EC). Chemical pre-treatment was used for the de-coating of WAC before its application in the EC process. A parameter study was then carried out in a batch monopolar EC cell with two chemically pre-treated WAC electrodes connected to an external DC Power supply to study the effects of current density (10 - 30 mA/cm2), initial pH (3 - 11), and initial dye concentration (50 - 250 mg/L) up to 30 min of reaction time. The best-operating conditions were found to be at a current density of 25 mA/cm2, an initial pH of 6.8 (original pH of dye) and an initial dye concentration of 100 mg/L with a nearly completed decolorization of 99.4 %. The kinetic model of the various current densities was well-fitted by the first-order reaction, with R2 values ranging from 0.8955 to 0.9914. The mathematical model for the decolorization rate of AR18 dye was successfully developed based on the reaction kinetics and empirical models. The predicted data was in good agreement with the experimental data to validate the developed mathematical model. The characterization analysis of the flocs confirmed that the main dye removal mechanisms were through charge neutralization, coagulation, and adsorption of dye onto the Al(OH)3 flocs. In conclusion, the WAC was successfully utilized as an effective electrode for the decolorization of AR18 dye via the EC process.

Electrocoagulation (EC) is one of the most effective electrochemical wastewater treatment techniques for removing color and organic pollutants from wastewater, and reducing sludge formation. In this study, the removal of Remazol Ultra Red RGB (reactive red 239) dye, which is used for commercial purposes, by the EC process was investigated. For this purpose, an electrochemical reactor was designed using monopolar parallel connected aluminum and iron electrodes. The effect of operational parameters such as the initial pH of the solution, current density, and electrolysis time were investigated to achieve higher color, Chemical Oxygen Demand (COD), and turbidity removal efficiency. The optimum conditions of the EC process were determined by evaluating the data obtained as a result of the experimental studies. It was observed that the removal efficiency increased with the increase of the electrolysis time and stabilized after 20 min. The optimum experiment conditions for the aluminum electrode were pH:3, current density of 50 A/m2, and conductivity of 250 μS/cm, for the iron electrode was pH: 5, current density of 75 A/m2, and conductivity of 500 μS/cm was found as. In all studies, the mixing speed was chosen as 250 rpm. As a result of this study, 95.49-99.94% color, 89.34-66.83% COD, and 92.18%-83.15% turbidity removal efficiencies were obtained with aluminum and iron electrodes under optimal conditions. Under optimum conditions, electrical energy consumption was calculated as 11.48 for Al, 6.60 kWh/m3 for Fe, and the energy consumption 0.56, 0.46 kg/m3. As a result of the experimental studies, high removal efficiencies were obtained in color, COD and turbidity removal with the EC process. As a result, it was concluded that EC treatment is an effective method for the purification of synthetic textile dyestuffs.

The electrocoagulation method was selected for the removal of Zn+2. The effects of the parameters such as current density, pH, and supporting electrolyte concentration on this method were studied. The Zn+2 concentration, mixing speed, and temperature were 250 mg/L, 150 rpm, and 293 K in the determination of the optimum pH the results obtained showed that a pH of 6 provided the highest Zn+2 removals. A pH of 6 was taken to be a constant optimum value while studying the effects of current density and supporting electrolyte concentration on removal. Current density values were chosen as 0.25, 0.50, 1.00, and 1.50 mA/cm2. Increasing current density increased Zn+2 removals significantly. Removal of 48.86%, 71.03%, 84.12%, and 97.39% were found for current densities of 0.25, 0.50, 1.00, and 1.50 mA/cm2 with an initial concentration of 250 mg/L with a reaction time of 30 minutes, respectively. An increase in current density caused an extreme increase in energy consumption. Energy consumption was 1.06 kW-h/m3 for a current density of 0.25 mA/cm2 with a reaction time of 30 minutes while it was 1.98, 3.46, and 5.31 kW-h/m3 for a current density of 0.50, 1.00, and 1.50 mA/cm2 at a pH of 6, respectively. It was found that the effect of supporting electrolyte concentration on removal efficiency was negative. Aluminum anodes were used in electrocoagulation processes. As supporting electrolyte concentration increased, removal efficiency decreased, and the energy consumption rate increased. It was determined, as the result of the experiments, that Zn+2 ions can be removed at the rate of 84.12% with a pH of 6, a 250 mg/L Zn+2 concentration, a 150 rpm mixing speed, a temperature of 293 K and a current density of 1.50 mA/cm2 in an aqueous solution.

Wastewater laden with toxic pollutants, such as chromium (Cr), can hurt humans, the environment, and aquatic life if not properly treated. The present work proposes to study the elimination of 100 mg/l of Cr(VI) ions from a synthetic wastewater effluent using a dynamic electrocoagulation process employing aluminum electrodes. The influences of several parameters are explored for the electrocoagulation process effectiveness in terms of Cr removal yield. This was done within the following ranges:  current density (5-22 mA/cm2), initial pH (2-7), and chromium concentration (25-150 mg/l). A settling step was followed to determine the total suspended solids content and the sludge volume index after electrocoagulation treatment. Depending on the operating conditions, the data of specific electrical energy consumption were employed to determine the best operating parameters of the process efficiency. Furthermore, data analysis (Scanning Electron Microscope, Fourier Transform Infrared spectroscopy, X-ray diffraction analysis, and X-ray fluorescence) of sludge formed after electrocoagulation showed an amorphous nature with a high content of aluminum and function groups that should have a potential to be utilized as coagulant/sorbent in wastewater treatment.

This study aims to apply the electrocoagulation (EC) process to eliminate a textile dye, in the case of Azucryl red (AR) using aluminum electrodes from recycled cans to obtain a perfect and economic elimination of the dye. The parameters followed in this electrocoagulation study are the initial pH, the distance between the electrodes, the intensity of the current, the salinity, and the initial concentration of the dye. We tested the effects of two types of electrodes: Aluminum in cans (recycled) and non-recycled aluminum. The results obtained for recycled aluminum electrodes made it possible to get discoloration rates of up to 99,76%, for an initial pH equal to 8 in a distance of 1 cm, an electrolysis time corresponding to 35 minutes, an imposed current of 0,25 A, a quantity of NaCl of 1 g/L, and 94,16% for non-recycled aluminum at t = 60 min. Modelization by the plan of experiments was carried out, and the models obtained by the complete factorial plan represent the experimental results well. According to the costs of treatment by electrocoagulation, we can consider that for intensity of 0,25 A (optimal intensity), the cost of treatment is 3,52.10-3 DZD (2,4.10-5 $) /L of water treated for electrodes made of non-recycled aluminum, and 6,63.10-4 DZD (4,4.10-6 $) /L of treated water for electrodes in cans.

The present work has been focused on the removal of fluoride from aqueous solutions through the electrocoagulation process. This work aimed to assess the efficiency of electrodes and electrocoagulation process in fluoride removal from aqueous solutions. Batch experiments were carried out using monopolar Iron and Copper electrodes as anode and cathode. Fluoride removal were influenced by operating variables such as current density, nature of electrodes, initial fluoride concentration and NaCl amount which have significant effects on removal efficiency. Indeed, the increase of current density from 0.18 to 27.8 mA/cm2, fluoride removal efficiency increased from 61 to 98% using Fe electrodes while 57 to 63% using Cu electrodes during the electrolysis time indicating the high capacity of Fe electrodes for fluoride removal. The addition of NaCl solution increased the fluoride removal efficiency from 65% to 70% using Fe electrodes. Kinetics modelling revealed that Fluoride was removed on the surface of Fe electrodes following a pseudo-second order kinetic while pseudo-first order kinetic using Cu electrodes. Maximum energy consumption was 70 kWh/m3 with water containing 0.5 g/L of NaCl while an energy of 45 kWh/m3 for water without NaCl. Consequently, electrocoagulation technology is a promising method for defluoridation of water using iron electrodes.

Pharmaceutical compounds such as Cefixime (CFX) as an antibiotic were detected in water resources. These compounds in water has caused many problems including bacterial resistance to antibiotics. Some processes have been used to remove these compounds from water sources. In this research the effect of electrocoagulation process was investigated on CFX removal from water. Experiments were carried out as a batch mode in electrochemical reactor that was made from Plexiglas with dimensions of 10×15×10 cm (1 L volume) and Aluminum/Aluminum electrodes (48 cm2 effective area) that immersed vertically, monopole configuration and in parallel. Central Composite Design (CCD) utilizing a response surface methodology (RSM) was used with experimental points of pH, Initial CFX concentration, current intensity and Reaction time and employed by different model such as linear, interaction and quadratic models. The results of this study showed that the efficiency of four dependent parameters on CFX removal represent with four linear and six interactions effects that the reaction time and initial concentration of CFX have the most positive and negative effects on the removal of CFX (%), respectively. The optimum conditions for the electrocoagulation process was pH=7.5, a primary concentration of CFX=5.75 mg/L, a current intensity=6.0 amperes and a reaction time=72.5 minutes (CFX removal=85.6%).

The development of treatment processes from laboratory scale to industries involves a lot of troubles due to the automation of process parameters and fluctuated characteristics of wastewater. In the present study, six different real-time textile effluents of samples such as S1 to S6 are characterized and treated by electrocoagulation process using Stainless Steel (SS) and Aluminum (Al) electrodes. The maximum removal efficiencies of color as 94%, turbidity as 99%, Chemical Oxygen Demand (COD) as 84% and Biological Oxygen Demand (BOD) as 82% is obtained for effluent sample S1 with fixed operational conditions such as the applied voltage of 4V, inter-electrode distance of 3 cm, the surface area of the electrode of 25 cm2 and agitation speed of 500 rpm respectively. After the electrocoagulation process, the BOD5/COD ratio of all effluent samples is observed as biodegradable limits. Under the fixed conditions, the operational cost for the treatment of effluent sample S1 analyzed as 2.42 and 1.01 $/m3 by using SS and Al electrodes respectively.

Electrocoagulation (EC) in a batch cell with Al anode and Fe cathode in monopolar parallel (MP) connection was used for the removal of basic dye, Bromophenol Blue (BPB). The effects of current density, pH, temperature and initial dye concentration, on the process were investigated. Equlibrium data were analyzed using four model equations: Langmuir, Freudlinch, Temkin and Dubinin–Radushkevich. Data obtained from the time dependent electrocoagulation removal of BPB were analyzed with pseudo-first-order, pseudo-second-order and Elovic kinetic models. The study showed that the process depend on current density, temperature, pH and initial dye concentration. The process attained equilibrium after 15 minutes at 30 oC, all the isotherm models fitted the data with R2 > 0.9. The maximum removal capacity Qm value of 166.50 mg g-1 was obtained for the study while the first order kinetic model best described the process based on the lower values of %SSE. The calculated thermodynamics parameters (∆Go, ∆Ho and ∆So) indicated that the process is spontaneous and endothermic in nature.

In this research, the efficiency of electrocoagulation treatment process using iron and aluminum electrodes to treat synthetic wastewater containing Reactive Red 24 (RR 24) was studied. The effects of parameters such as current density, pH, type of electrolyte, initial dye concentration, electrolyte concentration, temperature, and inter electrode distance on dye removal efficiency were investigated. The results showed that dye and chemical oxygen demand removals were 99.6% and 91.5% by using iron and were 97.9% and 83.8%, by using aluminum electrodes. The removal of dye exhibited pseudo first order with good correlation coefficients (0.955 and 0.990 for Fe and Al electrodes respectively. It can be concluded that electrocoagulation process by Iron electrode is very efficient and clean process for reactive dye removal from colored wastewater.

The Taguchi method was applied as an experimental design to determine optimum conditions for colour removal from azo dyes solutions containing remazol yellow G by electrocoagulation (EC) using iron and steel electrodes as anode and cathode, respectively. An orthogonal array (OA9) experimental design that allows to investigation the simultaneous variations of four parameters (initial remazol yellow G concentration, initial pH of the solution, time of electrolysis and current density) which have three levels was employed to evaluate the effects of experimental parameters. Performance measure analysis was followed by performing a variance analysis, in order to determine the optimum levels and relative magnitude of the effect of parameters. The desired characteristic for response has been elected as maximum decolourization. Therefore, Taguchi’s ‘the larger the better’ performance formula was used. The optimum conditions were found to be initial remazol yellow G concentration, 100 mg/l, initial pH of the solution 9, time of electrolysis, 25 min, and current density, mAcm-2.

The removal of color from synthetic wastewater containing Congo red was experimentally investigated using electrocoagulation process. The effects of operational parameters such as current density, electrolysis time, electrolyte concentration, electrode distance, initial dye concentration, initial pH and temperature on color removal efficiency were investigated in this study. The tentative results showed that Congo red in the aqueous phase was removed effectively by electrocagulation procedure. Optimum operating range for each of these operating variables was experimentally determined. Under the conditions of an initial dye concentration of 50mg/l, electrolysis time 5min, initial pH 7.5, current density 150A/ m2, sodium chloride concentration 10g/l, interelectrode distance 0.5 cm, the color removal efficiency reached 98% when electrical energy consumption in this conditions for the decolorization of the dye solution containing Congo red was 0.46 KWh/m3. Outcomes showed that the first-order rate equation could be described correlation for the decolorization rate of Congo red. The thermodynamic parameters, such as ΔHo, ΔSo and ΔGo, were also determined and evaluated. Further the experimental data were tested with different adsorption isotherm model to describe the electrocoagulation process.

Free cyanide and its related compounds are the most known contaminants which are released from industrial effluents to the environment; the objective of this study was to evaluate the efficiency electrocoagulation reactor with iron plate in order to find optimum operational conditions for cyanide removal from cyanide-containing effluents. The reactor was tested under different operational conditions of voltage (20, 30, and 40 V), detention time (20, 30, 40, 60, and 90 min), and influent concentration (20, 30 40, and 50 mg/l). Since ferrous ion capability to react with free cyanide and its related compounds are (97%) well established, iron plate was used as electrode in the present study. Additionally, to prevent creating ferric ion and ferric hydroxide precipitates in the reactor which decrease the removal efficiency, bisulfite was applied to hold ferrous ion in the reactor. The optimum operational conditions were obtained after running the reactor for several times. Based on the results, the optimum removal efficiency was obtained at voltage of 40 V, detention time of 90 min, and influent concentration of 50 mg/l. Therefore, this process may be considered as an alternative method for the removal of cyanide from cyanide- containing wastewaters.

The electrocoagulation (EC) is a simple and efficient method for the treatment of many water and wastewaters.The kinetics of decolorization of Acid Yellow 23 by EC using iron electrodes was studied. Theelectrodecolorization rate follows pseudo-first order kinetic with respect to the AY23 concentration havingkapp= 5.65 cm min-1 at T= 295 K. The rate equation is as follows:ln [AY23]t – ln [AY23]0 = -kapp2336 cm t250 cmThe pseudo-first order rate constant (kapp) is sensitive to the operational parameters. The kapp is low in bothhighly acidic and basic conditions. For the optimum operating conditions in electrodecolorization of AY23, theactivation energy was 41.15 kJ mol-1, sludge volume was about 8 ml from 250 ml of the original AY23 solution.The electrical energy consumption required for this treatment was 7.74 × 10-4 kW h and the electrodeconsumption was 37.4 mg.