RB5 Dye Research Articles

Explorations of physicochemical, photodegradation, phototoxicity, and kinetics of Bi2-2xCoxCdxO3/rGO nanocomposites for wastewater treatment applications

In recent times, there has been a pressing need to discover or manufacture a unique material that can serve as a photocatalyst for organic pollutants that are incapable of degradation. Pure Bi2O3 and Co, Cd co-doped Bi2-2xCoxCdxO3 (x = 0.8) nanoparticles were synthesized using the chemical co-precipitation method, but the new approach involves fabricating 10 % reduced graphene oxide Bi2-2xCoxCdxO3/rGO nanocomposites via the ultra-sonication route. This study investigated the effects of Co, Cd, and r-GO doping on the optical, electrochemical, structural, and photocatalytic properties of bismuth oxide. The synthesized nanomaterials were analyzed using X-ray diffraction (XRD), cyclic voltammetry, ultraviolet–visible (UV–Vis), Fourier transform infrared (FTIR), photoluminescence (PL), and Raman spectroscopy. The XRD patterns showed the formation of a monophasic monoclinic structure belonging to space group P21/c, with an average crystallite size estimated around 22–41 nm. According to the UV–visible study, the bandgap energy of Bi2O3 NPs, Bi2-2xCoxCdxO3 NPs, and Bi2-2xCoxCdxO3/rGO nanocomposites were 2.64 eV, 2.37 eV and 2.06eV respectively. The cyclic voltammetry technique was used to evaluate the functioning electrodes. In contrast to un-doped Bi2O3, the synergistic effects of Co, Cd, and r-GO on the substituted material increased the specific capacitance. The pure Bi2O3, doped Bi2-2xCoxCdxO3, and Bi2-2xCoxCdxO3/rGO photocatalyst degraded 62 %, 85 %, and 95.4 % respectively of RB-5 dye after 105 min of sunlight. The phytotoxicity analysis examined the germination of Hordeum vulgare seeds in treated and untreated RB-5 dyes. Additionally, scavenging investigations using reactive species trapping to confirm the dominant reactive species were evaluated. Bi2-2xCoxCdxO3/rGO nanocomposites are better at photocatalysis and have a narrow bandgap, which makes them useful as solar-active photocatalysts for getting rid of dyes in wastewater. In future, their composites with conducting polymers may improve their electrochemical and photocatalytic behaviour as well.

Analysis of the photocatalytic activity of La0.9Sr0.1Fe0.8Co0.2O3±δ perovskite as a catalyst in the degradation of RB-5 dye.

The photocatalytic efficiency of some semiconductors depends mainly on their morphological, optical, and structural properties, which can be modified by varying the calcination temperature. In order to evaluate how these properties change, as a function of temperature in a AA'BB'O3 perovskite material, La0.9Sr0.1Fe0.8Co0.2O3±δ (LSFC) was synthesized by the Pechini method and calcined at different temperatures (600 °C, 700 °C, 800 °C, and 900 °C). All the samples were characterized structurally, morphologically, and optically by XRD, SEM, and UV-Vis spectroscopy. Additionally, specific surface area and pore size distribution were calculated by BET and BHJ methods. LSFC was evaluated as photocatalyst material, estimating the degradation of reactive black 5 (RB5), employing as irradiation source UV light and sunlight. The obtained results display a clear tendency between the photoactivity and the heat treatment: degradation percentage decreases as the calcination temperature increases mainly due to the crystal and grain size and, furthermore, loss of porosity and the decrease in surface area, affecting the photocatalytic activity (98%, 95%, 74%, and 50% degradation, respectively). All the ceramic samples follow a pseudo-first-order reaction.

Nanostructured Mn–Ni Powders Produced by High-Energy Ball-Milling for Water Decontamination from RB5 Dye

In this study, the degradation efficiency of Mn-20at%Ni and Mn-30at%Ni particle powders made by melt-spinning and high-energy ball-milling techniques is investigated in relation to the degradation of the azo dye Reactive Black 5. SEM, EDS, and XRD were used to analyze the powders’ morphology, surface elemental composition, and phase structure. An ultraviolet-visible absorption spectrophotometer was used to measure the ball-milled powder’s capacity to degrade, and the collected powders were examined using the FTIR spectroscopy method to identify the substituents in the extract. The impact of MnNi alloy on the azo dye Reactive Black 5′s degradation and its effectiveness as a decolorizing agent were examined as functions of different parameters such as chemical composition, specific surface, and temperature. In comparison to the Mn-30at%Ni alloy, the powdered Mn-20at%Ni particles show better degrading efficiency and a faster rate of reaction. This remarkable efficiency is explained by the configuration of the valence electrons, which promotes more responding sites in the d-band when the Ni content is reduced. Therefore, increased electron transport and a hastened decolorization process are achieved by reducing the Ni concentration of RB5 solution with Mn80 particle powder. Additionally, this difference in their decolorization efficiency is explained by the fact that Mn-20at%Ni has the highest specific surface area of 0.45 m2 g−1. As the main result, the functional uses of nanostructured metallic powder particles as organic pollution decolorizers in the textile industry are greatly expanded by our study.

Modelization and optimization of the treatment of the reactive black-5 dye from industry effluents using experimental design methodology

This work investigated the coagulation-flocculation (CF) process of Reactive Black-5 (RB5) dye. The individual effects and interactions of different parameters, which include the pH, coagulant (Ferric chloride), and flocculant dosage (Himoloc DR3000), on the removal efficiency of RB-5 dye were studied. This study aims to build a mathematical model that allows for the representation of the studied responses according to different factors by using the experimental design methodology. The statistical fitness of the developed model was checked using analysis of variance (ANOVA). A second-order quadratic model, with a high determination coefficient (R2 =0.98% and R2=0.80% for chemical oxygen demand (COD) removal and overall cost, respectively), was best fitted to develop the relationship between independent and dependent variables. The results obtained show that the model was highly significant and in good agreement with the experimental results. The optimum conditions obtained for coagulant dose, flocculant dose, and pH were 550 mg/l, 210 mg/l, and 5.4, respectively. Under these optimal conditions, about 98% COD removal and 3.12 $/m3 for effluent treatment were achieved.

Evaluation of Original and Enzyme-Modified Fique Fibers as an Azo Dye Biosorbent Material

As natural fibers, low-cost biosorbents have proven to be an effective and clean tool to remove textile dyes from wastewater. In this research, the Reactive Black 5 removal ability of original and enzyme-modified natural fibers were assessed. A fiber extracted from a Colombian fique plant (Furcraea sp.) was employed. The effects of fique fiber protonation with different solvents and dye solution pH on RB5 removal were evaluated. The biosorbent chemical composition was modified using the commercial enzymes pectinase, ligninase, and xylanase. The point of zero charge (PZC) of the original and modified material was measured, and the dye removal capacity of the three enzyme-modified fibers was determined. Fiber protonation with 0.1 M HCl and a dye solution with pH of 2.4 increased the RB5 elimination to 49.1%. The change in the fiber chemical composition led to a reduction in the PZC from 5.5 to a 4.7–4.9 range. Pectinase-pretreated fique fibers presented the highest dye removal of 66.29%, representing a 36% increase in RB5 dye removal. Although the original fique fiber showed RB5 dye removal ability, its enzymatic modification changed the charge distribution on the fiber surface, improving the capture of dye molecules. Enzyme modification can be applied to obtain new functionalities for plant fibers as biosorbent materials.

Synergistic effect of CTAB on Reactive Black 5 removal performance of Candida tropicalis

This study provides a comprehensive review of the effect of cetyltrimethylammonium bromide on the Reactive Black 5 adsorptive behavior of Candida tropicalis. Adsorption studies examining the effects of process parameters have shown the critical roles of initial pH and surfactant concentration on the dye sorption capacity of the yeast. The remaining RB5 dye in the adsorption medium was determined colorimetrically via spectrophotometer. RB5 removal capacity was found as 126.1 mg RB5/g dry biomass with 61.1% yield in the presence of untreated dry sorbent in medium including 200 mg/L of RB5 at pH 2. Moreover, the maximum RB5 sorption capacities of untreated and CTAB treated dry biomass increased from 186.9 to 350.5 mg RB5/g dry biomass when initial RB5 concentration adjusted to 800 mg/L in pH 2. CTAB treated biomass performed significantly higher in all cases studied, due to the synergistic effect observed. It was seen that the experimental sorption data were compatible with the saturation type kinetic model. RB5 uptake equilibrium was quickly reached for both sorbents, and the Langmuir model described the equilibrium of RB5 biosorption with high accuracy.

Graphene quantum dot and iron co-doped TiO2 photocatalysts: Synthesis, performance evaluation and phytotoxicity studies

The present study reports the synthesis, photocatalytic decolorization of reactive black 5 dye and phytotoxicity of graphene quantum dots (GQDs) and iron co-doped TiO2 photocatalysts via modified sol gel method. GQDs were synthesized by direct pyrolysis of citric acid (CA). Scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS), Raman spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET) and photoluminescence spectroscopy (PL) were used to determine the physicochemical properties of the best performing photocatalysts. The results indicated improved physicochemical properties of GQD-0.1Fe-TiO2-300 with root mean square roughness (Rz) (33.82 nm), higher surface area (170.79 m2 g−1), pore volume (0.08 cm3 g−1), and bandgap (2.94 eV). Moreover, GQD-0.1Fe co-doping of TiO2 greatly improved the photocatalytic decolorization efficiency for RB5 dye. The photocatalytic reaction followed the pseudo first order reaction with gradual decrease in Kapp values for increment in RB5 concentration. The KC value was obtained as 2.45 mg L−1 min−1 while the KLH value was 0.45 L mg−1 indicating the heterogeneous reaction system followed the Langmuir-Hinshelwood isotherm and simultaneously occurring adsorption and photocatalytic processes. Photocatalytic reaction mechanism studies exhibited the holes and OH radicals as the main active species in the GQD-0.1Fe-TiO2-300 responsible for the decolorization of RB5. The proposed reaction pathway showed that both Fe-TiO2 and GQDs play important role in generation of electrons and holes. Additionally, GQD-0.1Fe-TiO2-300 were durable up to four cycles. Phytotoxicity assay displayed that treated water and best performing photocatalysts had no effect on Lycopersicon esculentum seed germination. Therefore, the proposed system can pave a viable solution for safe usage of dye loaded wastewater and effluent for irrigation after treatment.

CuO as efficient photo catalyst for photocatalytic decoloration of wastewater containing Azo dyes

Abstract Cupric oxide nanoparticles (CuO NPs) were prepared via a chemical precipitation method using the precursor of copper (II) nitrate trihydrate. X-ray diffraction analysis confirms that the CuO NPs were a monoclinic crystal structure. The energy band gap of CuO NPs was found to be about 1.76 eV. The obtained CuO NPs were used as a photo catalyst to decolorize various dyes, such as methylene blue (MB), acid yellow 23 (AY 23) and reactive black 5 (RB 5), with a low concentration in the presence of visible light. The results show that the highest decolorization achieved was 67.8% and 66.3% for RB-5 dye and AY-23 dye, while 43.5% for MB dye from aqueous solution at 5 h illumination. The obtained CuO NPs were used as a photo catalyst to decolorize various dyes, RB-5, AY-23 and MB dye obeys pseudo first order kinetics with values of −0.112, −0.174 and −0.201 h−1, respectively.

Site directed confinement of laccases in a porous scaffold towards robustness and selectivity

We immobilized a fungal laccase with only two spatially close lysines available for functionalization into macrocellular Si(HIPE) monoliths for the purpose of continuous flow catalysis. Immobilization (30–45 % protein immobilization yields) was obtained using a covalent bond forming reaction between the enzyme and low glutaraldehyde (0.625 % (w/w)) functionalized foams. Testing primarily HBT-mediated RB5 dye decolorization in continuous flow reactors, we show that the activity of the heterogeneous catalyst is comparable to its homogeneous counterpart. More, its operational activity remains as high as 60 % after twelve consecutive decolorization cycles as well as after one-year storage, performances remarkable for such a material. We further immobilized two variants of the laccase containing a unique lysine: one located in the vicinity of the substrate oxidation site (K157) and one at the opposite side of this oxidation site (K71) to study the effect of the proximity of the Si(HIPE) surface on enzyme activity. Comparing activities on different substrates for monoliths with differentially oriented catalysts, we show a twofold discrimination for ABTS relative to ascorbate. This study provides ground for the development of neo-functionalized materials that beyond allowing stability and reusability will become synergic partners in the catalytic process.

Photodegradation mechanism of the RB5 dye: A theoretical and spectroscopic study

Plasmonic photocatalysis has been widely applied in the photodegradation of organic dyes, allowing the use of visible light in the process. Specifically, Ag nanoparticles associated with ZnO have been used for the photodegradation of the azo dye RB5 under visible light irradiation. Experimental Raman and UV–vis spectral profile strongly indicated changes in the structure of the molecule, but the mechanism involved was not fully elucidated. In the present study, a photodegradation mechanism of the RB5 dye assisted by hydroxyl radicals was proposed, using computational simulation based on DFT method. Initially, a theoretical-experimental study of the tautomeric azo-hydrazo balance of RB5 was carried out, indicating predominance of the hydrazo form in aqueous solution greater than 99 %. Two sites were identified as favorable for hydroxyl radical attack, involving the CN bond breaking of the hydrazo species, resulting in two proposed products. The potential energy surface (PES) for the overall degradation process presented a favorable profile based on thermodynamic and kinetic parameters, indicating a spontaneous and rapid photodegradation, with a rate limiting barrier of 5.3 kcal mol−1 and –79.6 kcal mol−1 free energy. The theoretical spectral results for the proposed reagents and products are supported by previous experimental data and adds an efficient approach to the photodegradation mechanism of RB5, which could be extended for other azo dyes.

Photocatalytic membrane reactor based on Mexican Natural Zeolite: RB5 dye removal by photo-Fenton process

A Mexican natural zeolite (MNZ) of heulandite type was used to develop mesoporous cylindrical membranes based on the extrusion method, the mineral was previously mixed with additives to form a paste with 67.8% of solids. The membranes were calcined at 550 °C, the extruded parts suffered erosion upon water contact at lower calcination temperatures, while the structural properties such as surface area, pore volume and hardness were decreasing at higher temperatures. The MNZ had oxidation states Fe2+ and Fe3+ from the Fe3O4, and the bandgap was 2.42 eV. This cylindrical membrane was arranged as a photocatalytic membrane reactor (PCMR) to evaluate the RB5-dye removal by the Photo-Fenton process using a 2.2 W lamp as radiation source. The Fe effect in the solution and the permeation flow was analyzed at pH = 3, [H2O2] = 3 g/L, [RB5]0 = 100 mg/L, λmax = 405 nm (3.06 eV). The highest RB5-dye discoloration (D30% = 92.3) in the retained was obtained using Fe in solution and a permeation flow which did not show color signals from the reaction beginning (Dt% = 100). A pseudo-first order (n = 1) kinetics was assumed with an apparent kinetic constant of 0.0904 min−1 at the best reaction conditions. Finally, a total organic carbon removal TOC90% = 60.0 and TOC180% = 66.7 in the retentate flow was attained as well as TOC180% = 89.5 in the permeated flow.

Removal of reactive black 5 dye by using polyoxometalate-membrane

A POM-membrane was fabricated by immobilizing a keggin type polyoxometalate (POM) H5PV2Mo10O40 onto the surface of microporous flat-sheet polymeric polyvinylidene fluoride (PVFD) membrane using a chemical deposition method. The POM-membrane was characterized by FT-IR, SEM and EDX to confirm existing of the POM onto the membrane surface. The POM-membrane was used to remove an anionic textile dye (Reactive Black 5 named as an RB5) from aqueous phases with a cross-flow membrane filtration and a batch adsorption system. The dye removal efficiency of the POM-membrane using the cross-flow membrane filtration system and the batch adsorption system was about 88% and 98%, respectively. The influence factors such as contact time, adsorbent dosage, pH, and initial dye concentration were investigated to understand the adsorption mechanism of the RB5 dye onto the POM-membrane. To find the best fitting isotherm model, Langmuir, Freundlich, BET and Harkins-Jura isotherm models were used to analyze the experimental data. The isotherm analysis showed that the Langmuir isotherm model was found to the best fit for the adsorption data (R 2=0.9982, qmax=24.87 mg/g). Also, adsorption kinetic models showed the pseudo second order kinetic model was found the best model to fit the experimental data (R2=0.9989, q=8.29 mg/g, C0=15 ppm). Moreover, after four times regeneration with HNO3 acid, the POM-membrane showed high regenerability without losing dye adsorption capacity.

PbO2 decorated ZnO-TiO2 core-shell nanoflower structures by zinc anodising for photo- and anodic degradation of Reactive Black-5 dye

This work shows that metallic zinc can be used as a low-cost substrate or electrode for photocatalyst and electrocatalyst use by anodising in mild bicarbonate solution. Electrochemical anodising was used to produce ZnO nanowires by controlling operational conditions and dip-coating the anodised surface with TiO2 to produce a core-shell coating with photocatalytic properties. The PbO2, which is known as good electrocatalyst, was electrodeposited over the ZnO-TiO2 core-shell structure to alter its surface for electrocatalytic degradation of dye. The electrochemical and photocatalytic behaviours of the coatings were analysed for the removal of RB-5 dye as model pollutant. For the ZnO-TiO2 core-shell, the photocatalytic removal mechanism was driven by the heterojunction photocatalytic effect of photocatalytically active anatase TiO2 and wurtzite ZnO. Photocatalysis was switched to electrocatalytic behaviour after incorporation of PbO2. Although the UV light might be blocked by PbO2, the electrochemical degradation was enhanced due to the creation of ·OH free radicals over the PbO2 particles decorating a ZnO-TiO2 core-shell composite coating.

Adsorption of Reactive Black 5 azo dye from aqueous solution by using amine-functioned Fe3O4 nanoparticles with L-arginine: Process optimisation using RSM

ABSTRACT In the present study, the efficiency of amine-functioned Fe3O4 magnetic nanoparticles with L-arginine (Fe3O4@L-arginine) for the removal of RB5 azo dye from aqueous solution was investigated. Box–Behnken design was used to design the experiments and optimise the adsorption parameters. The results showed that Fe3O4@L-arginine nanoparticles were synthesised successfully. Optimum conditions for dye adsorption were obtained at a dye concentration of 50 mg/L, adsorbent dose of 0.8 g/L and pH 3 with an efficiency of 97.6% that was close to the model’s prediction percentage (96.8%), which confirms the validity of the model. The RB5 dye adsorption followed the pseudo-second-order kinetic model and the Temkin isotherm model, and the adsorption was a spontaneous endothermic process. The results illustrated that the Fe3O4@L-arginine nanoparticles can be used for RB5 dye adsorption by maintaining high efficiency for several times. Therefore, Fe3O4@L-arginine nanoparticles because of their high performance, easy synthesis and use and ease of separation are suitable adsorbents to remove dye from the coloured wastewater.

Electrochemical Degradation of Reactive Black 5 using two-different reactor configuration

Novel Sb-doped SnO2 ceramic electrodes sintered at different temperatures, are applied to the degradation of Reactive Black 5 in both divided and undivided electrochemical reactors. In the undivided reactor the discoloration of the solution took place via the oxidation of RB5 dye, without the corresponding reduction in the chemical oxygen demand for the ceramic electrodes. However, in the divided one, it was possible to achieve the discoloration of the solution while at the same time decreasing the chemical oxygen demand through the ·OH-mediated oxidation, although the chemical oxygen demand degradation took place at a slower rate.

Application of magnetic coagulant based on fractionated protein of Moringa oleifera Lam. seeds for aqueous solutions treatment containing synthetic dyes.

The aim of the present study was to evaluate the efficiency of a new magnetic coagulant, obtained from Moringa oleifera seeds protein functionalized with iron oxide nanoparticles to remove four anionic synthetic dyes with coagulation/flocculation assays followed by magnetic sedimentation. The results showed that the presence of a magnetic field during sedimentation considerably accelerates the separation and increases the dye removal efficiency. Amaranth dye removal increased from 45 to 86% and Sunset Yellow from 15 to 69% with the presence of magnetic field, while Reactive Black 5 and Brilliant Blue reached 94% and 52% removal, respectively. For AM and SY dyes, the best protein concentration is 150mgL-1, for RB5 dye is 115mgL-1, and for BB dye is 75mgL-1. The sedimentation time decreased from 30 to 5min with magnetic sedimentation. The residual value of AM dye decreased from 10.76mgL-1 to approximately 2.71mgL-1, and with SY the residual concentration decreased from approximately 16.79mgL-1 to 6.36mgL-1. The removal of BB and RB5 dyes reached an approximate final value of 48.2mgL-1 (52%) and 1.18mgL-1 (94%).

Adsorption of anionic dye (Reactive black 5) using macadamia seed Husks: Kinetics and equilibrium studies

Adsorption of Reactive black 5 dye currently used in textile industries was investigated using Macadamia Seed Husks (MSH) from a local Macadamia nut processing industry. Adsorption increased with increase in contact time, adsorbent dose and dye concentration. Conversely, the percentage dye adsorbed decreased with increase of solution pH and size of MSH particles. Sorption increased with an increase in temperature signaling an endothermic process. Batch adsorption data best fitted to Freundlich adsorption isotherm model with Kf value of 4.20679 and n = 2.3375. The adsorption kinetics followed a pseudo-second-order kinetic model with high correlation coefficients (R2 > 0.98). These results demonstrated that MSH is an environmentally friendly, locally available, effective and economical adsorbent for the removal of RB5 dye from industrial wastewaters.

Fe3+ @ ZnO/polyester based solar photocatalytic membrane reactor for abatement of RB5 dye

Abstract Heterogeneous photocatalysis, employing semiconductor metal oxides, especially at nano scale is a promising technique to mortify the dye residues from effluent. The photocatalysts on doping with a suitable dopant can be modified to enhance the photocatalytic activity. In this study, undoped and series of Fe3+ doped ZnO have been grown on polyester fabric through low temperature hydrothermal method to generate photocatalytic membrane reactors (PMRs). The material grown on the surface of fabric was characterized by XRD, EDX, SEM, TEM, STEM, AFM, XPS, ICP-MS, DRS and PL studies. For ZnO/PMR and Fe3+@ZnO/PMR photocatalytic activity was determined and examined to increase for Fe3+@ZnO/PMR in the solar region due to the reduction of band gap from 3.2 to 2.6 eV on Fe3+doping. The surface properties of PMRs were also determined by zeta potential and contact angle. The characterized ZnO and Fe3+@ZnO nano discs based PMRs have been used to degrade RB5 reactive dye on irradiating with artificial sunlight (D65, 72 W). The reaction parameters i.e. initial dye and oxidant concentration, pH and irradiation time have been optimized by Response Surface Methodology (RSM). The extent of dye degradation has been evaluated by UV/vis spectroscopy and FTIR. The maximum degradation achieved was 88.89% for ZnO/PMR and 98.34% for Fe3+@ZnO PMR in 180 min. The photocatalytic efficiency of Fe3+@ZnO PMR was investigated for 15 batches, with a slight gradual decrease in activity after eight batches.

Mass transport control of oxygen reduction at graphite felt with subsequent decolourisation of RB-5 dye in a parallel plate flow reactor

Abstract 3D Porous electrodes show excellent performance in industrial electrochemical engineering. Such electrodes perform better than planar electrodes in terms of their greater surface area, higher volumetric porosity, turbulence promotion of electrolyte and reasonable mass transfer rates. This paper considers the mass transfer studies of the oxygen reduction reaction (ORR) during the cathodic generation of H2O2 at carbon felt (CF) electrodes in a divided parallel plate electrochemical flow reactor. The volumetric mass transport coefficient obtained from voltammetric limiting current measurements increased at higher mean linear flow velocities in the rectangular channel of a parallel plate flow reactor. The cathodic compartment of the reactor has an equivalent diameter of 0.96 cm and it is separated from the anodic compartment by a cationic Nafion 115 membrane. A volumetric mass transfer coefficient (kmAe) of 0.74 s−1 was achieved at a mean linear flow velocity of 2.2 cm/s. Optimal conditions for H2O2 generation resulted in 95% Faradaic current efficiency and allowed up to 99% decolourisation of an organic RB-5 dye by electro Fenton oxidation.

Decolourization of dye solutions by electrocoagulation: an investigation of the effect of operational parameters

This study investigates the influence of the current density on both removal of reactive black 5 dye (RB5) from water and energy consumption using aluminium-based electrocoagulation (EC) reactor. The influence of the current density was investigated by electrolysing coloured water samples containing 25 mg/l of RB5 for 60 min at three different current densities (1, 2, and 3 mA/cm2). While the initial pH, distance between electrodes, flow rate, and initial temperature of water were kept constant at 5, 4 mm, 1 L/h, and 20 ± 10C, respectively. The obtained results showed that both the removal of RB5 dye and energy consumption increased with the increase of the applied current density. For example, it has been found that the removal RB5 and the power consumption increased from about 95% to 99.5%, and the power consumption increased from 4.3 to 10.4 kWh/m3 as the current density increased from 1 to 3 mA/cm2, respectively.