scholarly journals Efficiency of turbidity and BOD removal from secondarily treated sewage by electrochemical treatment

2012 ◽  
Vol 4 (2) ◽  
pp. 304-309 ◽  
Author(s):  
A. K. Chopra ◽  
Arun Kumar Sharma
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Supporting Electrolyte ◽  
Operating Time ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Effective Removal ◽  
Treated Sewage ◽  
Study Results

The present investigation observed the effect of operating time, current density, pH and supporting electrolyte on the removal efficiency of Turbidity (TD) and Biochemical oxygen demand (BOD) of secondarily treated sewage (STS) using electrochemical process. A glass chamber of 2 litre volume was used for the experiment with two electrode plates of aluminum, each having an area of 125 cm2 and 2 cm distance apart from each other. The treatment showed that the removal efficiency of TD and BOD increased to 87.41 and 81.38 % respectively with theincrease of current density (1.82 -7.52 mA/cm2), time (5 - 40 mins.) and different pH (4-8) of the STS. The most effective removal efficiency was observed around the pH 7. Further, 0.5 g/l NaCl as a supporting electrolyte for electrochemical treatment of STS was found to be more efficient for an increase to 95.56 % and 86.99 % for the removal of TD and BOD at 7.52 mA/cm2 current density in 40 mins. respectively. The electrode and energy consumption was found to vary from 2.52 x10-2 to 10.51 x10-2 kg Al/m3 and 2.76 kwh/m3 to 45.12 kWh/m3 depending on the operating conditions.The kinetic study results revealed that reaction rate (k) increased from 0.0174 to 0.03 min-1 for TD and 0.0169 to 0.024 min-1 for BOD with increase in current density from 1.82 to 7.52 mA/cm2.

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

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.

scholarly journals Electrocoagulation coupled with adsorption for effective removal of eosin yellow and nigrosin dyes in aqueous solution

2019 ◽  
Vol 11 (1) ◽  
pp. 97-106
Author(s):  
Vinothkumar K ◽  
Sugumaran T. ◽  
Venkateshwari S
Keyword(s):  
Electrical Conductivity ◽  
Current Density ◽  
Dye Removal ◽  
Adsorption Process ◽  
Supporting Electrolyte ◽  
Operating Time ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Effective Removal ◽  
Eosin Yellow

This paper deals with the study of suitability and efficiency of electrocoagulation (EC) coupled with adsorption to remove dye from synthetic dye solution. The EC cell consisted of mild steel (MS)/copper plates as electrodes and dye solution as electrolyte. The effects of operating time, concentration, supporting electrolyte, current density and pH have been investigated to find out the optimum operating conditions for EC. The concentration of dye was successfully reduced (EY) ?50% and Nigrosin dye ?99% during EC under the optimum operating conditions of initial concentration 0.5ppm, 20ppm, current density 0.04 A/cm2, 0.015 A/cm2, supporting electrolyte 4g, 4g, electrolysis time 20min, 10min, Eosin Yellow and Nigrosin dye respectively, the removal efficiency of the dyes were found 46.69% and 99%, electrical conductivity were 125.0 S/m and 105.7 S/m and TDS left in the EC treated solution were 82.0 and 69.3 ppt. Further proceedings with solution for adsorption process help to improve the dye removal. Results of the studies are electrical conductivity 20 S/m and TDS 30 ppt for EY, for Nigrosin 64.2 S/m and 42.1 ppt.

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

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.

Electrochemical Degradation of Phenol Using the Oxygen Diffusion Cathode in an Undivided Cell

2011 ◽  
Vol 183-185 ◽  
pp. 575-579
Author(s):  
Hui Wang ◽  
Zhao Yong Bian ◽  
Guang Lu ◽  
Xiang Jia Wei ◽  
Xiu Juan Yu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Supporting Electrolyte ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Degradation Pathway ◽  
Phenol Removal ◽  
Electrochemical Degradation ◽  
Undivided Cell

Electrochemical degradation of phenol was studied in an undivided cell with a Ti/IrO2/RuO2 anode and a carbon/polytetrafluoroethylene (C/PTFE) O2-fed cathode which produced hydrogen peroxide (H2O2) by the electro-reduction of dissolved oxygen. The effect of current density, supporting electrolyte concentration and initial pH on the removal efficiency of phenol were investigated systematically. Results indicated that the optimal removal efficiency of phenol was achieved under the conditions of current density of 39 mA/cm2 and supporting electrolyte concentration of 0.02 mol/L. The phenol removal efficiency in the neutral condition was higher than that of acidic and basic conditions. The chemical oxygen demand (COD) and total organic carbon (TOC) removal achieved 71.6% and 63.6% for 100 min’s electrolysis, respectively. Benzoquinone, maleic acid, oxalic acid, acetic acid and formic acid were identified as intermediates by HPLC. A general phenol degradation pathway involving all these intermediates was proposed.

Electrochemical Treatment of Simulated Dye Wastewater

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.

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

2014 ◽  
Vol 50 (2) ◽  
pp. 198-209 ◽  
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.

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

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
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.

scholarly journals Application of electrochemical treatment for the removal of triazine dye using aluminium electrodes

2020 ◽  
Vol 69 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Sakthisharmila Palanisamy ◽  
Palanisamy Nachimuthu ◽  
Mukesh Kumar Awasthi ◽  
Balasubramani Ravindran ◽  
Soon Woong Chang ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Electrical Energy ◽  
Reactive Dye ◽  
Product Formation ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Spectral Studies ◽  
Textile Dye ◽  
Electrode Consumption ◽  
Electrocoagulation Process

Abstract Textile effluents contain triazine-substituted reactive dyes that cause health problems such as cancer, birth defects, and hormone damage. An electrochemical process was employed effectively to degrade azo reactive dye with the aim of reducing the production of carcinogenic chemicals during biodegradation. Textile dye C.I. Reactive Red 2 (RR2), a model pollutant that contains dichloro triazine ring, was subjected to the electrocoagulation process using aluminium (Al) electrodes. A maximum of 97% of colour and 72% of chemical oxygen demand (COD) removal efficiencies were achieved and 9.5 kWh/kg dye electrical energy and 0.8 kg Al/kg dye electrode consumption were observed. The dye removal mechanism was studied by analysing the results of UV-Vis spectra of RR2 and treated samples at various time intervals during electrocoagulation. Fourier transform infrared (FTIR) spectra and energy dispersive X-ray (EDX) spectral studies were used for analysing the electrocoagulated flocs. The results indicate that in this process the dye gets removed by adsorption and there is no significant carcinogenic by-product formation during the degradation of dye.

Decontamination of synthetic textile wastewater by electrochemical processes: energetic and toxicological evaluation

2012 ◽  
Vol 66 (12) ◽  
pp. 2586-2596 ◽  
Author(s):  
Y. Mountassir ◽  
A. Benyaich ◽  
M. Rezrazi ◽  
P. Berçot ◽  
L. Gebrati
Keyword(s):  
Current Density ◽  
Organic Contaminants ◽  
Operating Time ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Toxicological Evaluation ◽  
Textile Materials ◽  
Titanium Electrode ◽  
Electrochemical Processes ◽  
Influence Of Ph

The treatment of a synthetic textile wastewater, prepared with several compounds used in the finishing of textile materials, was comparatively studied by electrochemical methods such as electrooxidation (EO) (titanium electrode) and electrocoagulation (EC) (with aluminum and iron electrodes). The influence of pH, current density and operating time on the treatment was assessed by the parameters used to measure the level of organic contaminants in the wastewater; i.e. color, toxicity and chemical oxygen demand (COD). The experimental results showed that an effective electrochemical oxidation was achieved in which the wastewater was decolorized and 92% of COD was completely eliminated. In particular, the mineralization took place by indirect oxidation, mediated by active chlorine, and the treatment efficiency was enhanced by the addition of NaCl to the wastewater and by increasing the applied current density. The toxicity, still higher than the toxicity of the raw effluent, indicated a presence of toxic products after EO. Good results were obtained with the Al and Fe electrodes, mainly with respect to the removal of color and toxicity. EC is more economical than EO and the toxicity evaluation with the Daphnia magna test shows a significant reduction after EC.

scholarly journals Removal of Polyvinyl Alcohol Using Photoelectrochemical Oxidation Processes Based on Hydrogen Peroxide Electrogeneration

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kai-Yu Huang ◽  
Chih-Ta Wang ◽  
Wei-Lung Chou ◽  
Chi-Min Shu
Keyword(s):  
Hydrogen Peroxide ◽  
Light Intensity ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Current Density ◽  
Uv Light ◽  
Supporting Electrolyte ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
Solution Ph

This study investigates the removal efficiency of PVA from aqueous solutions using UV irradiation in combination with the production of electrogenerated hydrogen peroxide (H2O2) at a polyacrylonitrile-based activated carbon fiber (ACF) cathode. Three cathode materials (i.e., platinum, graphite, and ACF) were fed with oxygen and used for the electrogeneration of H2O2. The amount of electrogenerated H2O2produced using the ACF cathode was five times greater than that generated using the graphite cathode and nearly 24 times greater than that from platinum cathode. Several parameters were evaluated to characterize the H2O2electrogeneration, such as current density, oxygen flow rate, solution pH, and the supporting electrolyte used. The optimum current density, oxygen flow rate, solution pH, and supporting electrolyte composition were found to be 10 mA cm−2, 500 cm3 min−1, pH 3, and Na2SO4, respectively. The PVA removal efficiencies were achieved under these conditions 3%, 16%, and 86% using UV, H2O2electrogeneration, and UV/H2O2electrogeneration, respectively. A UV light intensity of 0.6 mW cm−2was found to produce optimal PVA removal efficiency in the present study. A simple kinetic model was proposed which confirmed pseudo-first-order reaction. Reaction rate constant (kap) was found to depend on the UV light intensity.

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