Type Of Supporting Electrolyte Research Articles

Hierarchical flower-like SrHPO4 electrodes for the photoelectrochemical degradation of Rhodamine B

SrHPO4 films were deposited on fluorine doped tin oxide coated glass (FTO) substrate by cathodic electrodeposition method for photoelectrocatalytic (PEC) oxidation of Rhodamine B (RhB). The as-prepared films were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy system (EDXS) and atomic force microscope (AFM). The effect of different parameters on the RhB electrochemical degradation, including supporting electrolyte type and concentration, current density, pH, and initial dye concentration, is studied. The most efficient conditions were found to be a current density of 10 mA cm−2, NaCl as a supporting electrolyte with a concentration of 0.1 M and a neutral medium which is favorable for HClO oxidizing species generation. Compared to photocatalysis and electrocatalysis, the photoanode displayed more superior photoelectrodegradation efficiency. Indeed, 94.5% removal of RhB (10 mg/L) in 12 min is obtained. This good efficiency is due to the synergetic effect induced by combining electrodegradation with UV-light energy. The reached electrocatalytic performance of SrHPO4 makes it a new promising photoanode for the treatment of wastewaters contaminated by organic pollutants.

Electrooxidation of nonylphenol ethoxylate-10 (NP10E) in a continuous reactor by BDD anodes: optimisation of operating conditions

ABSTRACT Electrooxidation (ELOX) of synthetic and real wastewater containing nonylphenol ethoxylate-10 (NP10E) surfactant as a model pollutant was investigated using a boron-doped diamond anode (BDD) in a continuous reactor in the presence of Na2SO4 or NaCl supporting electrolyte. Response surface methodology (RSM) with there factors and five coded levels (Central Composite Design, CCD) was used to optimise the continuous ELOX process performing 17 runs for each supporting electrolyte type. Individual and interactive effects of process variables such as initial pH of synthetic wastewater, current density and electrolysis time on NP10E electrooxidation were investigated in terms of COD, TOC, and NP10E removal efficiencies. It was found that NP10E to be more efficiently electrooxidized when NaCl was used as the supporting electrolyte. Under the optimal experimental conditions (initial pH 8, current density of 250 A/m2 and electrolysis time of 45 min) for electrooxidation of synthetic wastewater, the removal efficiencies were 91.6%, 94.3% and 85.3% with the operating cost of 0.90 US$/m3 for COD, TOC, and NP10E, respectively. In the studies conducted with real wastewater, obtained results were very close to these results. And also, kinetic studies were performed to find the reaction rate coefficient at the optimum conditions. Based on the type of supporting electrolyte the COD removal rates were fitted first order and zero-order reaction kinetic rules for Na2SO4 and NaCl, respectively.

Electrooxidation of short and long chain perfluorocarboxylic acids using boron doped diamond electrodes

This study investigates electrooxidation of short (C3-C6) and long (C7-C-18) chain perfluorocarboxylic acids (PFCAs) including perfluorooctane sulfonate (PFOA) using Si/BDD electrode. The effect of operational parameters (supporting electrolyte type, applied current density, and initial pH) were explored for PFOA removal. At the optimized conditions, 74% TOC removal and 37% defluorination ratio were gained for 10 mg L-1 of PFOA solution which evidences that the shorter chain PFCAs were formed. The PFOA degradation pathway followed one direct electron transfer from PFOA molecule to anode surface. Then two different degradation pathways were proposed. The first proposed degradation mechanism involved the reaction of perfluoroheptyl radical and hydroxyl radical, the release of HF and hydrolysis. The second mechanism involved the reaction between perfluoroheptyl radical and O2, formation of C7F15O and perfluorohexyl radical with releasing COF2. The removal of short- (C3-C6) and long-chain PFCAs (C7-C18) was also characterized. More than 95% of removal efficiency was gained for all long-chain PFCAs, excluding C7. The removal ratios of short-chain PFCAs (C3-C6) were 39%, 41%, 66% and 70% for C3, C4, C5 and C6, respectively. Contrary to long-chain PFCAs, chain-length dependence for short-chain PFCAs were observed. Defluorination ratio of short-chain PFCAs was only 45% signifying that defluorination partially occurred. Water matrix did not significantly affect the degradation of short-chain PFCAs in deionized water (DI), river water and secondary effluent of a wastewater treatment plant (WWTP). In contrast, defluorination ratio of long-chain PFCAs was noticeably affected by water matrix with the order of DI water > WWTP effluent > river water.

A novel electrochemical sensor based on a glassy carbon electrode modified with dendrimer functionalized magnetic graphene oxide for simultaneous determination of trace Pb(II) and Cd(II)

In this work, a glassy carbon electrode (GCE) coated with poly(amidoamine) dendrimer functionalized magnetic graphene oxide (GO-Fe3O4-PAMAM) was applied for the simultaneous detection of Pb(II) and Cd(II) in environmental waters. The square wave anodic stripping voltammetry (SWASV) method was employed for the determination of target metal ions after closed-circuit mode. The effects of different experimental variables such as supporting electrolyte type, preconcentration solution pH, accumulation potential, accumulation time and concentration of dropped GO-Fe3O4-PAMAM nanocomposite were investigated and optimized. At optimal chemical and electrochemical conditions, the designed sensor showed linear voltammetric responses in the ranges of 0.4–120 μg L−1 for Pb(II) and 0.2–140 μg L−1 for Cd(II) with coefficients of determination higher than 0.99. Low detection limits of 130 ng L−1 for Pb(II) and 70 ng L−1 for Cd(II) were also achieved. Beside, possible interferents of some metal ions including Tl(I), Cu(II), Zn(II), Hg(II), Co(II), Mg(II), Ca(II), Mn(II), Ni(II), Fe(III), In(III) and Cr(III) were examined but did not cause any significant interferences. Finally, the present assay was employed for the simultaneous detection of both cations in real water samples, and the obtained results were verified by inductively coupled plasma mass spectrometry (ICP-MS) as a confirmatory method.

Adsorptive stripping voltammetric method for the determination of caffeine at integrated three-electrode screen-printed sensor with carbon/carbon nanofibers working electrode

A commercially available screen-printed carbon electrode coated with carbon nanofibers (SPCE/CNFs) and differential-pulse adsorptive stripping voltammetry (DPAdSV) were used to determination of caffeine. The process of electrochemical oxidation of caffeine in 0.1 mol L−1 sulfuric acid at the SPCE/CNFs surface was investigated by cyclic voltammetry (CV). The effect of the supporting electrolyte type, pH and concentration, time and potential of accumulation, amplitude and scan rate were studied to select the optimum experimental conditions. Under the optimized conditions, the well-defined caffeine peak was observed at 1.25 V (vs. screen-printed silver reference electrode) in 0.1 mol L−1 sulfuric acid. The caffeine was accumulated at − 0.8 V for 60 s. The oxidation peak current was proportional to concentration of caffeine from 2.0 × 10−7 to 1.0 × 10−6 mol L−1 with detection limit of 5.6 × 10−8 mol L−1. The presented method has been successfully applied for the determination of caffeine in beverage samples.

Decoration of graphene oxide with NiO@polypyrrole core-shell nanoparticles for the sensitive and selective electrochemical determination of piceatannol in grape skin and urine samples

For the first time, we developed an electrochemical sensor for piceatannol based on a new type of nanocomposite: graphene oxide nano sheets decorated with core-shell NiO@polypyrrole nanoparticles (NiO@Ppy/GO) mixed with nafion and casted on the surface of glassy carbon electrode. The nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR) techniques. The square wave voltammetry as a sensitive technique and cyclic voltammetry were selected for the quantification of piceatannol in 0.1 M phosphate buffer solution (pH 7.0). Several parameters were evaluated such as pH value, scan rate and supporting electrolyte type for the determination of piceatannol. In addition, selectivity and repeatability measurements were also evaluated. Under the optimized conditions, linear range and limit of detection were obtained 0.01–10.0 µM and 0.003 µM, respectively. Relative standard deviation for 3.0 µM and 6.5 µM were calculated 3.25% and 1.83%, respectively. The proposed sensor was applied successfully for the quantification analysis of piceatannol in grape skin essential oil and urine sample with satisfactory results.

Photo-electro-Fenton process applied to the degradation of valsartan: Effect of parameters, identification of degradation routes and mineralization in combination with a biological system

In this work, the oxidation of the antihypertensive drug valsartan by the Electro-Fenton (EF) and photo-electro-Fenton (PEF) processes was studied using a Ti/IrO2 doped with SnO2 as anode, and a carbon felt air diffusion electrode as cathode. Initially, the influence of variables such as supporting electrolyte type, current density, and pH on EF and/or PEF processes was evaluated. The processes were carried out in batch mode, in an open and undivided cell of 200 cm3. The efficiency of the systems was evaluated in terms of the removal of the initial contaminant and rate of mineralization. When NaCl was used as a supporting electrolyte at pH 3.0 and current density 3.46 mA/cm2 adding 3.6 × 10−5 mol/L of Fe2+, total valsartan (20 mg/L) degradation was observed after 45 min. After 120 min, even if total removal of valsartan was reached, only 25% of mineralization was obtained. Thus, valsartan degradation tests at near neutral pH in presence of oxalic acid (4.6 × 10−5 mol/L) lead to comparable results with those obtained at pH 3.0. Primary aromatic intermediates were identified by high resolution mass spectrometry (HRMS) using hybrid quadrupole- time-of-flight (QTOF) MS, from which an initial degradation pathway was proposed. At the end of the PEF system, several aliphatic acids were accumulated and observed, which were effectively removed in a subsequent aerobic biological system. The results demonstrate the feasibility of PEF and biological coupling process to completely mineralize emerging pharmaceutical pollutants, such as valsartan, at natural pH.

Comparison of plain and indoline modified mercury film electrodes for determination of lead, cadmium and copper in urine samples by anodic stripping voltammetry

The objective of this work is to assess response characteristics of conventional mercury film (MFE) and (poly)indoline modified mercury film electrodes (ICMFE) in determination of Cu, Pb and Cd ions by voltammetric stripping analysis. Parameters regarding to mercury and polymer film formations (such as potential, electrochemical mode chosen for film growth, polymer and mercury film thicknesses) and supporting electrolyte type and pH in stripping analysis were thoroughly studied, and conditions providing the highest and most stable responses for the three test metal ions were determined for both electrode types. Performances of the electrodes were evaluated in terms of sensitivity and selectivity in both synthetic aqueous solutions and urine samples. Responses at ICMFE were invariably much lower compared to that obtained at plain MFE. Decomposition of urine samples by hot mineral acid gave rise to enhanced responses at both electrodes. However, ICMFE always exhibited negative selectivity toward Cd even in acid decomposed urine samples. Reliability of the concentration values calculated by the method of standard addition in complex matrices, such as urine, was discussed comprehensively on statistical basis.

Veratric acid removal from water by electrochemical oxidation on BDD anode

The efficiency of boron doped diamond (BDD) in the electrochemical treatment of synthetically contaminated water with veratric acid (VA), one kind of polyphenolic type compounds, is investigated in this work. A BDD electrode was practically fabricated using hot filament chemical vapor deposition (HFCVD). Later on, the BDD electrode was implemented as an anode in a batch electrolytic reactor. The effect of operating factors such as the initial concentration of VA, NaCl addition, and supporting electrolyte type (H2SO4, H3PO4 and Na2SO4) was studied. The chemical oxygen demand (COD) measurements were conducted to study the VA electrolysis kinetics. The experimental data suggested that sodium sulfate was the best supporting electrolyte as the COD removal reached a percentage of 100% using 1 mmol/dm3 as VA concentration. The kinetics of the COD decay of the VA electrolysis were found to obey the pseudo-first order model. Remarkably, the electrolysis process is significantly speeded up once chloride is added to the reaction. The complete COD removal was achieved in 60 minutes of treatment.

Potentiostatic electrodeposition of a novel cost effective PbO2 electrode: Degradation study with emphasis on current efficiency and energy consumption

Electrochemical oxidation is developing as a prominent technology for the degradation of organic contaminants. Even though many electrode materials proved efficient in degradation of organics, the quest for a stable, low cost electrode material is still at large. The present study attempted the development of an efficient and cost effective electrode material, PbO2 electrodeposited on mild steel. The optimum operating range of parameters for the electrodeposition was established. Compact structure of PbO2 was obtained up to an applied voltage of 2V. Concentration of PbO also affected the morphology at lower concentration. XRD analysis depicted that the deposit consists of a mixture of α and β-PbO2, and non-stoichiometry of the deposited PbO2 was proved by EDX analysis. Applied current, initial dye concentration, supporting electrolyte type and concentration affected the reaction kinetics, current efficiency and energy consumption in the degradation of methyl orange on MS/PbO2 electrode. A current efficiency of 57% and corresponding energy consumption of 42kWhkgCOD−1 treated was obtained at 88% COD degradation for an initial COD of 292mgL−1 with current density of 2.87mAcm−2. The newly developed MS/PbO2 electrode had current efficiency and energy consumption comparable with data reported in literature at similar degradation conditions.

Mechanistic Switching by Hydronium Ion Activity for Hydrogen Evolution and Oxidation over Polycrystalline Platinum Disk and Platinum/Carbon Electrodes

AbstractFundamental electrochemical reactions, namely the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR), are re‐evaluated under various pH conditions over polycrystalline Pt disk electrodes and Pt/C electrodes to investigate the overpotential and Tafel relations. Kinetic trends are observed and can be classified into three pH regions: acidic (1–5), neutral (5–9), and alkaline (9–13). Under neutral conditions, in which H2O becomes the primary reactant, substantial overpotential, which is not affected by pH and the supporting electrolyte type, is required for electrocatalysis in both directions. This ion independence, including pH, suggests that HER/HOR performance under neutral conditions solely reflects the intrinsic electrocatalytic activity of Pt in the rate determining steps, which involve electron transfer with water molecules. A global picture of the HER/HOR, resulting from mechanistic switching accompanied by change in pH, is detailed.

Effect of some operational parameters on the arsenic removal by electrocoagulation using iron electrodes.

Arsenic contamination of drinking water is a global problem that will likely become more apparent in future years as scientists and engineers measure the true extent of the problem. Arsenic poisoning is preventable though as there are several methods for easily removing even trace amounts of arsenic from drinking water. In the present study, electrocoagulation was evaluated as a treatment technology for arsenic removal from aqueous solutions. The effects of parameters such as initial pH, current density, initial concentration, supporting electrolyte type and stirring speed on removal efficiency were investigated. It has been observed that initial pH was highly effective on the arsenic removal efficiency. The highest removal efficiency was observed at initial pH = 4. The obtained experimental results showed that the efficiency of arsenic removal increased with increasing current density and decreased with increasing arsenic concentration in the solution. Supporting electrolyte had not significant effects on removal, adding supporting electrolyte decreased energy consumption. The effect of stirring speed on removal efficiency was investigated and the best removal efficiency was at the 150 rpm. Under the optimum conditions of initial pH 4, current density of 0.54 mA/cm2, stirring speed of 150 rpm, electrolysis time of 30 minutes, removal was obtained as 99.50%. Energy consumption in the above conditions was calculated as 0.33 kWh/m3. Electrocoagulation with iron electrodes was able to bring down 50 mg/L arsenic concentration to less than 10 μg/L at the end of electrolysis time of 45 minutes with low electrical energy consumption as 0.52 kWh/m3.

Effect of electrode material and supporting electrolyte on the treatment of water containing Escherichia coli by electrocoagulation

Laboratory experiments were carried out to investigate the mechanisms of electrochemical disinfection of artificial wastewater contaminated by Escherichia coli culture (5 × 105 UFC/100 mL) using electrocoagulation. In order to go deeply into the mechanism of the process, the behaviors of two dissolved-type electrodes (ordinary steel and aluminum) and a non-dissolved-type (carbon graphite) electrode were compared. The ordinary steel electrode was found more efficient for E. coli cells destruction compared to aluminum and carbon graphite electrodes. In order to determine the most favorable condition for the treatment, the effect of various supporting electrolytes including, sodium chloride, sodium sulfate and sodium nitrate, was scrutinized. E. coli is inactivated by 5 log units for a charge loading of 37.30 F/m3 for sodium sulfate, 24.87 F/m3 for sodium nitrate and 12.43 F/m3 for sodium chloride. It thus appears that the most favorable supporting electrolyte type for this method of disinfection is sodium chloride, a fact which can be explained by the formation of disinfectant by-products such as chlorine dioxide, hypochlorite ions and perchlorate ions. From the results obtained, electrocoagulation applied to the elimination of E. coli proceeds through three combined effects: the electric field, the actions of oxidants electrogenerated during the process and the adsorption by the metallic hydroxides formed in solution.

고체 고분자 전해질(SPE)을 이용한 전기분해 공정에서 Rhodamine B 분해

Objectives: Feasibility of electrochemical oxidation of the aqueous non-biodegradable wastewater such as cationic dye Rhodamine B (RhB) has been investigated in an electrochemical reactor with solid polymer electrolyte (SPE). Methods: Nafion 117 cationic exchange membrane as SPE has been used. Anode/Nafion/cathode sandwiches were constructed by sandwiching Nafion between two dimensionally stable anodes (JP202 electrode). Experiments were conducted to examine the effects of applied current (0.5~2.0 A), supporting electrolyte type (0.2 N NaCl, <TEX>$Na_2SO_4$</TEX>, and 1.0 g/L NaCl), initial RhB concentration (2.5~30.0 mg/L) on RhB and COD degradation and <TEX>$UV_{254}$</TEX> absorbance. Results: Experimental results showed that an increase of applied current in electrolysis reaction with solid polymer electrolyte has resulted in the increase of RhB and <TEX>$UV_{254}$</TEX> degradation. Performance for RhB degradation by electrolyte type was best with NaCl 0.2 N followed by SPE, and <TEX>$Na_2SO_4$</TEX>. However, the decrease of <TEX>$UV_{254}$</TEX> absorbance of RhB was different from RhB degradation: SPE > NaCl 0.2 N > <TEX>$Na_2SO_4$</TEX>. RhB and <TEX>$UV_{254}$</TEX> absorbance decreased linearly with time regardless of the initial concentration. The initial RhB and COD degradation in electrolysis reaction using SPE showed a pseudo-first order kinetics and rate constants were 0.0617 (<TEX>$R^2=0.9843$</TEX>) and 0.0216 (<TEX>$R^2=0.9776$</TEX>), respectively. Conclusions: Degradation of RhB in the electrochemical reactor with SPE can be achieved applying electrochemical oxidation. Supporting electrolyte has no positive effect on the final <TEX>$UV_{254}$</TEX> absorbance and COD degradation. Mineralization of COD may take a relatively longer time than that of the RhB degradation.

Electrochemical degradation of methylene blue using electrodes of stainless steel net coated with single-walled carbon nanotubes

In the present study, an electrochemical technique was used for degradation of methylene blue (MB) from aqueous solutions on a laboratory scale using a homemade plexiglass cell. Electrodes comprising a stainless steel net coated with single-walled carbon nanotubes (SWCNTs@SSN) were used as both the anode and the cathode. The effects of various parameters, including the supporting electrolyte type, solution pH, electrochemical time, applied voltage, electrolyte concentration, and initial MB concentration, on the MB decolorization efficiencies were investigated. The percentage of chemical oxygen demand (COD) removal was also investigated. The supporting electrolyte type, applied voltage, and electrolyte concentration have obvious effects on the degradation of MB, and the solution pH and initial MB concentration have minor effects on the degradation. As the initial MB concentration was varied from 100 to 400 mg L−1, the percentages of COD removal of all the investigated solutions were higher than 86.0%, and the general current efficiency (GCE) increased from 1.79 to 6.38%. The electrical energy consumption (Ec) increased with increasing applied voltage. The results of the study prove that the method is a potential technique for the treatment of azo dye wastewater.

Treatment of Endocrine Disrupting Chemical From Aqueous Solution by Electrocoagulation

The removal of endocrine disrupting chemical (BPA; Bisphenol–A) from aqueous solution was experimentally investigated by electrocoagulation process. The effects of different combinations of aluminum (Al) and iron (Fe) electrode pair, supporting electrolyte type, supporting electrolyte concentration, initial pH and applied current density and initial BPA concentration on the Chemical Oxygen Demand (COD), and energy consumption performances were critically evaluated. The experiment results indicate that Al–Al electrode pair is the most efficient choice of the four electrode pairs. The COD removal efficiency was increased when NaCl was used as the supporting electrolyte instead of Na2SO4 and NaNO3. The optimum supporting electrolyte type and its concentration, initial pH, applied current density and treatment time were found to be NaCl, 0.05 M, pH 7.0, 12 mA cm−2 and 40 min, respectively. Energy consumption was found to decrease with increase of NaCl concentration while it increases with increasing applied current density. The initial and treated sample was characterized by UV–vis spectroscopy to confirm the treatment efficiency. The sludge formed during electrocoagulation was characterized by XRD and SEM/EDAX analysis.

Optimization of specific energy consumption for Bomaplex Red CR-L dye removal from aqueous solution by electrocoagulation using Taguchi-neural method

In this investigation, firstly, Taguchi method was applied to determine the optimum specific energy consumption (SEC) for dye removal from aqueous solution by electrocoagulation using aluminum electrodes. An orthogonal array (OA16) experimental design that allows to investigate the simultaneous variations of five parameters (Initial dye concentration, Initial pH of the solution, Supporting electrolyte concentration, Supporting electrolyte type and Current density) having four levels was employed to evaluate the effects of experimental parameters with two replicates. According to Taguchi-neural method, while the optimum conditions that dye removal efficiency equals to 62.71 % were found to be initial dye concentration 600 mg/L, initial pH of the solution 6, supporting electrolyte concentration 7.0 mM, supporting electrolyte type NaCl, and current density 0.10 mA/cm2. Under these optimum conditions, energy consumption is 0.38 kW h/m3. Alternatively, it can be said that optimum conditions can be modified as follows supporting electrolyte concentration of 10.0 mM and supporting electrolyte type CaCl2, for 600 mg/L, initial dye concentration initial pH of the solution 6, and current density 0.10 mA/cm2. Under these optimum conditions, SEC and dye removal efficiency are 0.45 kW h/m3 and 69.18 %, respectively.

Effect of activated carbon fiber anode structure and electrolysis conditions on electrochemical degradation of dye wastewater

The alizarin red S (ARS) in simulated dye wastewater was electrochemically oxidized using an activated carbon fiber (ACF) felt as an anode. The influence of electrolytic conditions and anode structure on the dye degradation was investigated. The results indicated that initial pH, current density and supporting electrolyte type all played an important role in the dye degradation. The chemical oxygen demand (COD) removal efficiency of dye solution in neutral or alkaline medium was about 74% after 60 min of electrolysis, which was higher than that in acidic medium. Increasing current density would lead to a corresponding increase in the dye removal. The addition of NaCl could also improve the treatment effect by enhancing the COD removal efficiency 10.3%. For ACF anodes, larger specific surface area and higher mesopore percentage could ensure more effective electrochemical degradation of dye. The data showed that the color removal efficiency increased from 54.2 to 83.9% with the specific surface area of ACF anodes increasing correspondingly from 894 to 1682 m 2/g.

Electro-Fenton treatment of dye solution containing Orange II: Influence of operational parameters

The electro-Fenton process was used to assess the decoloration of Orange II in aqueous solutions. Hydrogen peroxide (H 2O 2) was electro-generated by reduction of dissolved oxygen (DO) in acidic solutions containing dilute supporting electrolyte. This oxidation process allows the production of active intermediates, which react on the organic compounds, leading to their mineralization. Decoloration experiments were performed in the presence of perchlorate, chloride and sulfate electrolyte media at pH 3.0 under potential controlled electrolysis conditions. Effect of operational parameters such as cathodic potential, oxygen mass flow rate and inert supporting electrolyte type and concentration were investigated to find the best experimental conditions for achieving overall dye decoloration. Complete decoloration of Orange II occurs in less than 90 min. In addition, effect of cathode surface area and electrolyte concentration in the accumulation of H 2O 2 and behavior of the Fe 3+/Fe 2+ in the electro-Fenton system was examined. Results show that potential of −0.5 V vs. SCE, 0.05 M NaClO 4 electrolyte, O 2 sparging rate of 8 ml/min and diluted dye concentration were the best conditions for decoloration of the Orange II by electro-Fenton process. The mineralization of the initial pollutant was investigated by total organic carbon measurements that show a 75% mineralization of 2 × 10 −5 M dye at 180 min. Also, degradation by-products were identified with GC–MS analysis.

Optimization of Bomaplex Red CR-L dye removal from aqueous solution by electrocoagulation using aluminum electrodes

In this paper, Taguchi method was applied to determine the optimum dye removal from aqueous solution by electrocoagulation using aluminum electrodes. An orthogonal array (OA 16) experimental design that allows to investigate the simultaneous variations of five parameters (initial dye concentration, initial pH of the solution, supporting electrolyte concentration, supporting electrolyte type and current density) having four 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. Because the desired characteristic for response has been maximum decolorization, Taguchi's ‘the larger the better’ performance formula was used. While the optimum conditions were found to be initial dye concentration of 100 mg/L, initial pH of the solution of 3, supporting electrolyte concentration of 0.0 mM, supporting electrolyte type of CaCl 2 and current density of 0.50 mA/cm 2. Under these optimum conditions, energy consumption is 0.607 kWh/kg dye, when the system evaluated also based on the energy consumptions it can be said that optimum conditions should be modified as follows: supporting electrolyte concentration of 2.5 mM; supporting electrolyte type NaCl, for 100 mg/L initial dye concentration; initial pH of the solution of 3; current density of 0.50 mA/cm 2.