Electrocatalytic degradation of bromocresol green wastewater on Ti/SnO2-RuO2 electrode

Thermal decomposition method was employed to prepare a Ti/SnO2-RuO2 electrode, on which electrocatalytic degradation of bromocresol green (BCG) was investigated in detail. Scanning electron microscopy, an X-ray diffraction analyzer and an X-ray fluorescence spectrometer were adopted to characterize the morphology, crystal structure and element analysis of the as-prepared Ti/SnO2-RuO2 electrode. It was indicated that the Ti/SnO2-RuO2 electrode had a ‘cracked-mud’ structure and exhibited a superior specific surface area. The removal efficiency of BCG on the Ti/SnO2-RuO2 electrode was determined in terms of chemical oxygen demand and ultraviolet-visible absorption spectrometry. The results of the batch experiment indicated that the removal efficiency of BCG was influenced by the following factors in descending order: initial pH0, reaction temperature, current density and electrolysis time. The removal efficiency of BCG reached up to 91% at the optimal experiment conditions (initial concentration of 100 mg L−1, initial pH0 7, reaction temperature of 30 °C, current density of 12 mA cm−2 and electrolysis time of 150 min). As a result, it was concluded that BCG wastewater was efficiently removed by electrochemical oxidation on the Ti/SnO2-RuO2 electrode.

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Treatment of dairy wastewaters by electrocoagulation using iron electrodesTraitement des eaux résiduaires d'une laiterie par électrocoagulation avec des électrodes de fer

Water Quality Research Journal ◽

10.2166/wqrjc.2014.053 ◽

2014 ◽

Vol 50 (2) ◽

pp. 198-209 ◽

Cited By ~ 1

Author(s):

Malika Aoudjehane ◽

Mohamed Elghazali Benatallah

Keyword(s):

Electrical Conductivity ◽

Removal Efficiency ◽

Current Density ◽

Oxygen Demand ◽

Operating Conditions ◽

Electrolysis Time ◽

Electrode Consumption ◽

Treatment Conditions ◽

Consumption Energy ◽

Optimal Efficiency

A procedure of electrocoagulation (EC) using iron electrodes has been used for the treatment of the wastewaters produced by the Beni-Tamou dairy in Algeria. The effect of the operating conditions, such as the current intensity, the electrolysis time, the pH of the solution and the electrical conductivity, on the removal efficiency of chemical oxygen demand (COD) and the total suspended solids (TSS) has been studied. An inter-electrode distance of 1 cm has been maintained constant during the tests. It has been found that an increase in electrolysis time and current density improved the treatment significantly, albeit with a greater consumption of energy as well as an increased electrode consumption. The results of the electrocoagulation treatment under various operating conditions show that the optimal efficiency has been obtained under the following conditions: 60 minutes of electrolysis, a current density of 200 A/m2, a pH 8, an electrical conductivity of 4.72 mS/cm and a consumption energy of 13.57 kWh/m3. Under these conditions, the removal efficiency for the COD and TSS parameters is 93.26 and 99.3%, respectively. The optimal treatment conditions of dairy wastewaters have resulted in final COD and TSS concentrations of 41.5 and 27 mg/L, respectively, values that are conform to industrial liquid effluents discharge norms.

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Electrochemical Treatment of Simulated Dye Wastewater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.441.555 ◽

2012 ◽

Vol 441 ◽

pp. 555-558

Author(s):

Feng Tao Chen ◽

San Chuan Yu ◽

Xing Qiong Mu ◽

Shi Shen Zhang

Keyword(s):

Current Density ◽

Oxygen Demand ◽

Electrochemical Treatment ◽

Dye Wastewater ◽

Electrolysis Time ◽

Electrochemical Degradation ◽

Mild Conditions ◽

Thermal Decomposition Method ◽

Initial Ph ◽

Effects Of Ph

The Ti/SnO2-Sb2O3/PbO2 electrodes were prepared by thermal decomposition method and its application in the electrochemical degradation of a heteropolyaromatic dye, Methylene blue (MB), contained in simulated dye wastewater were investigated under mild conditions. The effects of pH, current density and electrolysis time on de-colorization efficiency were also studied. Chemical oxygen demand (COD) was selected as another parameter to evaluate the efficiency of this degradation method on treatment of MB wastewater. The results revealed that when initial pH was 6.0, current density was 50 mA·cm2, electrolysis time was 60 min, Na2SO4 as electrolyte and its concentration was 3.0 g·dm3, the de-colorization and COD removal efficiency can reach 89.9% and 71.7%, respectively.

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Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

Water Science & Technology ◽

10.2166/wst.2018.376 ◽

2018 ◽

Vol 78 (6) ◽

pp. 1260-1267 ◽

Cited By ~ 9

Author(s):

Mohammad Malakootian ◽

Mohammad Reza Heidari

Keyword(s):

Reaction Time ◽

Removal Efficiency ◽

Current Density ◽

Steel Industry ◽

High Efficiency ◽

Oxygen Demand ◽

Optimal Conditions ◽

Suitable Alternative ◽

Steel Mills ◽

Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

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Optimization of electrocoagulation of instant coffee production wastewater using the response surface methodology

Polish Journal of Chemical Technology ◽

10.1515/pjct-2017-0030 ◽

2017 ◽

Vol 19 (2) ◽

pp. 67-71 ◽

Cited By ~ 6

Author(s):

Ha Manh Bui

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Removal Efficiency ◽

Current Density ◽

Cod Removal ◽

Coefficient Of Determination ◽

Electrolysis Time ◽

Instant Coffee ◽

Operating Variables ◽

Initial Ph

Abstract The COD removal efficiency from an instant coffee processing wastewater using electrocoagulation was investigated. For this purpose, the response surface methodology was employed, using central composing design to optimize three of the most important operating variables, i.e., electrolysis time, current density and initial pH. The results based upon statistical analysis showed that the quadratic models for COD removal were significant at very low probability value (<0.0001) and high coefficient of determination (R2 = 0.9621) value. The statistical results also indicated that all the three variables and the interaction between initial pH and electrolysis time were significant on COD abatement. The maximum predicted COD removal using the response function reached 93.3% with electrolysis time of 10 min, current density of 108.3 A/m2 and initial pH of 7.0, respectively. The removal efficiency value was agreed well with the experimental value of COD removal (90.4%) under the optimum conditions.

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Electrochemical Degradation of Crystal Violet Using Ti/Pt/SnO2 Electrode

Applied Sciences ◽

10.3390/app11188401 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8401

Author(s):

Rachid El Brychy ◽

Mohamed Moutie Rguiti ◽

Nadia Rhazzane ◽

Moulay Driss Mellaoui ◽

Khalid Abbiche ◽

...

Keyword(s):

Removal Efficiency ◽

Crystal Violet ◽

Current Density ◽

Ph Value ◽

Supporting Electrolyte ◽

Chloride Concentration ◽

Oxygen Demand ◽

Electrochemical Treatment ◽

Electrochemical Process ◽

Initial Ph

Today, organic wastes (paints, pigments, etc.) are considered to be a major concern for the pollution of aqueous environments. Therefore, it is essential to find new methods to solve this problem. This research was conducted to study the use of electrochemical processes to remove organic pollutants (e.g., crystal violet (CV)) from aqueous solutions. The galvanostatic electrolysis of CV by the use of Ti/Pt/SnO2 anode, were conducted in an electrochemical cell with 100 mL of solution using Na2SO4 and NaCl as supporting electrolyte, the effect of the important electrochemical parameters: current density (20–60 mA cm−2), CV concentration (10–50 mg L−1), sodium chloride concentration (0.01–0.1 g L−1) and initial pH (2 to 10) on the efficiency of the electrochemical process was evaluated and optimized. The electrochemical treatment process of CV was monitored by the UV-visible spectrometry and the chemical oxygen demand (COD). After only 120 min, in a 0.01mol L−1 NaCl solution with a current density of 50 mA cm−2 and a pH value of 7 containing 10 mg L−1 CV, the CV removal efficiency can reach 100%, the COD removal efficiency is up to 80%. The process can therefore be considered as a suitable process for removing CV from coloured wastewater in the textile industries.

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Treatment of vinegar industry wastewater by electrocoagulation with monopolar aluminum and iron electrodes and toxicity evaluation

Water Science & Technology ◽

10.2166/wst.2019.013 ◽

2018 ◽

Vol 78 (12) ◽

pp. 2542-2552 ◽

Cited By ~ 1

Author(s):

Seval Yılmaz ◽

Emine Esra Gerek ◽

Yusuf Yavuz ◽

Ali Savaş Koparal

Keyword(s):

Removal Efficiency ◽

Current Density ◽

Oxygen Demand ◽

Electrical Current ◽

Cod Removal ◽

Toxicity Tests ◽

Polyaluminum Chloride ◽

Chemical Complexity ◽

Iron Electrodes ◽

Industry Wastewater

Abstract We present electrocoagulation (EC) treatment results of vinegar industry wastewater (VIW) using parallel plate aluminum and iron electrodes, and analyze the toxicity of the treatment processes. Due to the chemical complexity of vinegar production wastewater, several parameters are expected to alter the treatment efficiency. Particularly, current density, initial pH, Na2SO4 as support electrolyte, polyaluminum chloride (PAC) and kerafloc are investigated for their effects on chemical oxygen demand (COD) removal. Following several treatment experiments with real wastewater samples, aluminum-plate electrodes were able to reach to a removal efficiency of 90.91% at pH 4, 10 mg/L PAC and an electrical current density of 20.00 mA/cm2, whereas iron-plate electrodes reached to a removal efficiency of 93.60% at pH 9, 22.50 mA/cm2 current density. Although EC processes reduce COD, the usefulness of the system may not be assessed without considering the resultant toxicity. For this purpose, microtox toxicity tests were carried out for the highest COD removal case. It was observed that the process reduces toxicity, as well as the COD. Consequently, it is concluded that EC with aluminum and iron electrodes is COD removal-wise and toxicity reduction-wise a plausible method for treatment of VIW, which has high organic pollutants.

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Simultaneous decolorization of binary mixture of Reactive Yellow and Acid Violet from wastewaters by electrocoagulation

Water Science & Technology ◽

10.2166/wst.2011.306 ◽

2011 ◽

Vol 63 (8) ◽

pp. 1644-1650 ◽

Cited By ~ 2

Author(s):

Can Serkan Keskin ◽

Abdil Özdemir ◽

İ. Ayhan Şengil

Keyword(s):

Removal Efficiency ◽

Current Density ◽

Oxygen Demand ◽

Cod Removal ◽

Time Duration ◽

Synthetic Dye ◽

Nacl Concentration ◽

Optimum Ph ◽

Dyestuff Wastewater ◽

Acid Violet

Dyes are common pollutants in a large variety of industrial wastewaters, and the treatment of these wastes has been extensively studied by coagulation. For the removal of pollutants from the wastewaters, different techniques have been used and electrocougulation is one of the widely used methods. This process is very effective in removing organic pollutants including dyestuff wastewater. The purposes of this study were to investigate the effects of the operating parameters, such as current density, electrolyte concentration, dyestuff concentration, and pH of solution on decolorization and chemical oxygen demand (COD) removal of wastewater containing two different dyes in same solution by direct current electrocoagulation. The amount of dye removed was found by application of first derivative spectrophotometric method to the synthetic dye mixtures. In this work synthetic dye mixture which include C.I. Reactive Yellow 145 (RY145) and C.I. Acid Violet 90 (AV 90) were used for electrocougulation (EC) process with iron electrodes. In the presence of both dye molecules, the optimum pH was found to be 4, optimum NaCl concentration was 3000 mg/L and optimum current density was 5.56 mA/cm2. Under these conditions in the case of 100 mg/L−1 each dye concentration at 20°C and 3 cm interelectro distance the color removal efficiency was reached 97.7% for AV 90 and 97.1% for RY145 in 10 minutes time duration. Dye concentration dependent highest COD removal efficiency was measured as 82% around at 100 mg/L dye concentration.

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Electrocoagulation for spent coolant from machinery industry

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2017.057 ◽

2017 ◽

Vol 8 (4) ◽

pp. 497-506 ◽

Cited By ~ 1

Author(s):

W. Pantorlawn ◽

T. Threrujirapapong ◽

W. Khanitchaidecha ◽

D. Channei ◽

A. Nakaruk

Keyword(s):

Energy Consumption ◽

Current Density ◽

Specific Energy ◽

Specific Energy Consumption ◽

Oxygen Demand ◽

Cod Removal ◽

Industrial Wastes ◽

Electrolysis Time ◽

Current Densities ◽

Sludge Production

Abstract Spent coolant is considered as one of the most polluting industrial wastes and causes environmental problems. It mostly contains high non-biodegradable organic carbon and oil contents; the biodegradability index was very low at 0.04, which is difficult to be effectively treated by common treatment systems. Electrocoagulation (EC) was proposed for a pre-treatment of coolant. The laboratory-scale of EC reactor was developed with Al electrodes and 10 mm of interelectrodes. The efficiency of the EC reactor on chemical oxygen demand (COD) removal was investigated at various current densities and electrolysis times. The highest current density of 50 mA/cm2 induced a short electrolysis time of 10 min to reach the steady state of approximately 65% COD removal. When lower current densities of 20–40 mA/cm2 were supplied to the EC reactor, COD removal efficiency of 65% can be achieved at longer electrolysis times. According to the specific energy consumption and sludge production, the optimal condition for spent coolant treatment was the current density of 20 mA/cm2 and electrolysis time of 30 min in which a COD removal of efficiency of 68% was obtained, 0.88 kWh/kg-COD of the specific energy consumption and 0.04 kg/kg-COD of the sludge production.

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Optimization of process parameters for the electrochemical oxidation treatment of petroleum refinery wastewater using porous graphite anode

Al-Qadisiyah Journal for Engineering Sciences ◽

10.30772/qjes.v13i2.652 ◽

2020 ◽

Vol 13 (2) ◽

pp. 125-135

Author(s):

Ahmad Salah Fahim ◽

Ali H. Abbar

Keyword(s):

Removal Efficiency ◽

Current Density ◽

Petroleum Refinery ◽

Oxygen Demand ◽

Chloride Ion ◽

Electrochemical Reactor ◽

Electrochemical Treatment ◽

Operating Conditions ◽

Graphite Anode ◽

Porous Graphite

The present paper deals with the electrochemical treatment of wastewaters generated from Al-Diwaniyah petroleum refinery plant in a batch electrochemical reactor using stainless steel cathode and porous graphite anode. Effects of operating parameters such as current density (5-25mA/cm2), pH (3-9), addition of NaCl (0-2g/l), and time (20–60min) on the removal efficiency of chemical oxygen demand (COD) were investigated. The results revealed that both pH and NaCl addition have the main effect on the COD removal efficiency confirming that the system was governed by reaction conditions in the bulk of solution not upon the electro oxidation of chloride ion on the surface of the electrode. Parametric optimization was carried out using Response Surface Methodology (RSM) combined with Box–Behnken Design (BBD) to maximize the removal of COD. Under optimized operating conditions of initial pH: 3, current density = 25 mA/cm2, NaCl conc. = 2g/l, and time = 60 min, the removal efficiency of COD was found to be 98.16% with energy consumption of 9.85 kWh/kgCOD which is relatively lower than the previous works.

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Organic Pollutants Removal from Olive Mill Wastewater Using Electrocoagulation Process via Central Composite Design (CCD)

Water ◽

10.3390/w13243522 ◽

2021 ◽

Vol 13 (24) ◽

pp. 3522

Author(s):

Abeer El Shahawy ◽

Inas A. Ahmed ◽

Mahmoud Nasr ◽

Ahmed H. Ragab ◽

Saedah R. Al-Mhyawi ◽

...

Keyword(s):

Weight Loss ◽

Current Density ◽

Operating Cost ◽

Oxygen Demand ◽

Olive Mill Wastewater ◽

Cod Removal ◽

Electrolysis Time ◽

Faraday’S Law ◽

Central Composite ◽

Olive Mill

Electrocoagulation (EC) was studied in this study as a potential alternative approach for treating Olive Mill Wastewater (OMW). Aluminum plates were utilized as anode and cathode to evaluate the removal of Chemical Oxygen Demand (COD) from OMW and the aluminum electrode’s weight loss. Central Composite Experimental Design (CCD) and Response Surface Methodology were used to optimize its performance. Anodes were weighed before and after each electrocoagulation experiment, to compare the experimental and the theoretical dissolved aluminum weights calculated using Faraday’s law. We discovered the following EC conditions for CCD: current density = 15 mA/cm2, pH = 4, and electrolysis time of 30 min. Under these conditions, the maximum COD removal ratio was 41%, equating to an Al weight loss of 288.89 g/m3 at an estimated operating cost of 1.60 USD/m3. According to the response optimizer, the most economical operating settings for COD removal efficiency of 58.888% are pH 4, a current density of 18.41 mA/cm2, electrolysis time of 36.82 min, and Al weight loss of 337.33 g/m3, with a projected running cost of 2.00 USD/m3.

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