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 Evaluation of the efficiency of electrocoagulation process in removing cyanide, nitrate, turbidity, and chemical oxygen demand from landfill leachate

2021 ◽  
Vol 8 (3) ◽  
pp. 237-244
Author(s):  
Abdoliman Amouei ◽  
Mehdi Pouramir ◽  
Hosseinali Asgharnia ◽  
Mahmoud Mehdinia ◽  
Mohammad Shirmardi ◽  
...  
Keyword(s):  
Reaction Time ◽  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Current Density ◽  
Oxygen Demand ◽  
Contamination Level ◽  
Municipal Solid Wastes ◽  
Electrocoagulation Process ◽  
Length Width ◽  
Time Parameters

Background: Leachate contains toxic and non-biodegradable substances that are not easily treated by conventional treatment methods. This study investigated the effect of pH, current density, and reaction time parameters on the removal of cyanide (CN- ), nitrate (NO3- ), turbidity, and chemical oxygen demand (COD) from leachate by electrocoagulation process. Methods: This study was an experimental one with direct current using four parallel bipolar aluminum electrodes with 90% purity. The length, width, and thickness of the electrodes were 5 cm, 10 cm, and 2 mm, respectively. There were 6 holes with a diameter of 0.7 cm on each of the electrodes. The samples were prepared from the old leachate of solid waste landfill in Ghaemshahr, Iran. Results: In this study, at a current density of 33 mA/cm2 and a time of 60 minutes, the optimum removal efficiency of cyanide (100 %) was obtained at pH 5.5 and pH 10. Moreover, the maximum removal of nitrate (99.65 %) and turbidity (86.41 %) were at pH 5.5 and pH 8.3, respectively and the highest removal efficiency of COD (83.14 %) was obtained at pH 10. Conclusion: The results showed that the removal of cyanide, nitrate, turbidity, and COD increases with increasing current density and reaction time. Due to the proper removal of nitrate and cyanide from leachate by electrocoagulation, nitrate and cyanide amounts were less than the allowable contamination level. Based on the results, electrocoagulation is considered an efficient and effective method for removing nitrate and cyanide from old leachate of municipal solid wastes.

scholarly journals Simultaneous nitrate and organic matter removal from a dairy effluent by biodenitrification

2018 ◽  
Vol 31 (2) ◽  
pp. 97-107
Author(s):  
Ahmed Hamdani ◽  
Mohammed Mountadar ◽  
Omar Assobhei
Keyword(s):  
Organic Matter ◽  
Chemical Oxygen Demand ◽  
Electron Donor ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Nitrite Accumulation ◽  
Simultaneous Removal ◽  
Optimal Conditions ◽  
Dairy Effluent ◽  
Organic Removal

In order to study the simultaneous removal of nitrate and organic matter from a dairy effluent containing 670 mg∙L-1 of nitrate (NO3--N) and 5 760 mg∙L-1 of dissolved chemical oxygen demand (CODd), denitrification in a laboratory scale bioreactor consisting of an immersed bacterial bed colonized by an heterotrophic denitrifying flora (HDF) selected for NO3- reduction, COD consumption and adapted to grow on an effluent produced by a dairy industry was investigated. The obtained results indicated that at the optimal conditions of temperature (30°C), pH (7), COD/NO3--N ratio (5), the operation lasted 108h with total reduction of nitrate in 72h, no nitrite accumulation, and 92% of soluble COD removal in 96h. This indicates that the biodenitrification was accompanied with a high efficiency of matter organic removal as an electron donor, and thereby satisfies the applicable standards.

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.

scholarly journals Application of a Continuous Bipolar Mode Electrocoagulation (CBME) system for polishing distillery wastewater

2019 ◽  
Vol 93 ◽  
pp. 02005 ◽  
Author(s):  
Madhuri Damaraju ◽  
Debraj Bhattacharyya ◽  
Tarun Panda ◽  
Kiran Kumar Kurilla
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Optimal Point ◽  
Suitable Alternative ◽  
Toc Removal ◽  
Bipolar Mode ◽  
Recalcitrant Carbon ◽  
Initial Ph ◽  
Distillery Wastewater ◽  
Experimental Values

A continuous bipolar mode electrocoagulation (CBME) unit was used in this study for polishing a biologically treated distillery wastewater at laboratory scale. This study focuses on optimizing the process for removal of Total Organic Carbon (TOC) from an anaerobically-treated distillery wastewater. Response surface methodology (RSM) was used for optimizing the process. The study was conducted by varying three operating parameters: Initial pH (2-10), reaction time (0.5-15 min), and current density (13-40 A/sqm). High R-square values, above 0.9, were obtained with ANOVA. Optimal point was observed to be at pH-6.04, Reaction time-11.63 min, current density-39.2 A/sqm. Experimental values of TOC removal at optimal point were found to be 73% against maximum predicted value of 79%. Color removal efficiency was observed to be 85% at the optimal points. It can be concluded that CBME system can be a suitable alternative for removal of recalcitrant carbon and color post-biological treatment in distillery wastewaters.

The removal of the trivalent chromium from the leather tannery wastewater: the optimisation of the electro-coagulation process parameters

2011 ◽  
Vol 63 (3) ◽  
pp. 385-394 ◽  
Author(s):  
E. GilPavas ◽  
I. Dobrosz-Gómez ◽  
M. Á. Gómez-García
Keyword(s):  
Current Density ◽  
Oxygen Demand ◽  
Trivalent Chromium ◽  
Biological Oxygen Demand ◽  
Optimal Conditions ◽  
Electrode Gap ◽  
Surface Method ◽  
Response Capacity ◽  
Electro Coagulation ◽  
Parameter Values

The capacity of the electro-coagulation (EC) process for the treatment of the wastewater containing Cr3+, resulting from a leather tannery industry placed in Medellin (Colombia), was evaluated. In order to assess the effect of some parameters, such as: the electrode type (Al and/or Fe), the distance between electrodes, the current density, the stirring velocity, and the initial Cr3+ concentration on its efficiency of removal (%RCr+3), a multifactorial experimental design was used. The %RCr3+ was defined as the response variable for the statistical analysis. In order to optimise the operational values for the chosen parameters, the response surface method (RSM) was applied. Additionally, the Biological Oxygen Demand (BOD5), the Chemical Oxygen Demand (COD), and the Total Organic Carbon (TOC) were monitored during the EC process. The electrodes made of aluminium appeared to be the most effective in the chromium removal from the wastewater under study. At pH equal to 4.52 and at 28°C, the optimal conditions of Cr3+ removal using the EC process were found, as follows: the initial Cr3+ concentration=3,596 mg/L, the electrode gap=0.5 cm, the stirring velocity=382.3 rpm, and the current density=57.87 mA/cm2. At those conditions, it was possible to reach 99.76% of Cr3+removal, and 64% and 61% of mineralisation (TOC) and COD removal, respectively. A kinetic analysis was performed in order to verify the response capacity of the EC process at optimised parameter values.

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 Application of Fe2O3/ZrO2 loaded polyhedron ball on photocatalytic degradation of diesel pollutants in seawater under visible light

2020 ◽  
Vol 81 (9) ◽  
pp. 1983-1993
Author(s):  
Liping Wang ◽  
Xiaocai Yu ◽  
Jiaqi Liao ◽  
Bining Xue ◽  
Siyao Tian ◽  
...  
Keyword(s):  
Reaction Time ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Calcination Temperature ◽  
Removal Efficiency ◽  
H2o2 Concentration ◽  
Optimal Conditions ◽  
Photocatalytic Removal ◽  
Marine Diesel ◽  
Doping Ratio

Abstract Fe2O3/ZrO2 nanocomposite photocatalyst was successfully prepared by coprecipitation method for the degradation of diesel pollutants in seawater under visible light. The effects of doping ratio, calcination temperature, photocatalyst dosage, initial diesel concentration, H2O2 concentration, and reaction time on the photocatalytic removal efficiency were investigated. Moreover, the optimal conditions for Fe2O3/ZrO2 nanocomposite photocatalyst to degrade marine diesel pollution were determined. The removal efficiency of diesel by nanocomposite photocatalyst could reach 97.03%. A photocatalyst-loaded polypropylene polyhedral ball was prepared, and the removal efficiency of diesel by photocatalyst-loaded polypropylene polyhedral ball decreased from 99.35 to 68.84% after four recycling cycles.

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

2018 ◽  
Vol 78 (12) ◽  
pp. 2542-2552 ◽  
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.

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

2016 ◽  
Vol 75 (1) ◽  
pp. 220-227 ◽  
Author(s):  
Hongmei Bai ◽  
Ping He ◽  
Jingchao Chen ◽  
Kaili Liu ◽  
Hong Lei ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Reaction Temperature ◽  
Current Density ◽  
Oxygen Demand ◽  
Bromocresol Green ◽  
Electrolysis Time ◽  
Element Analysis ◽  
Visible Absorption ◽  
X Ray ◽  
Electrocatalytic Degradation

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.

Edible Plant Oil Wastewater Treatment Using Electro-Fenton Technique: Experiment and Correlation

2018 ◽  
Vol 16 (8) ◽  
Author(s):  
Reza Davarnejad ◽  
Seyed Amir Mohajerani
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Interactive Effects ◽  
Molar Ratio ◽  
Plant Oil ◽  
Edible Plant ◽  
High Chemical Oxygen Demand

Abstract The edible plant oil production factories consume high amounts of water and contaminate the water resources. This type of wastewater consists of high chemical oxygen demand (COD) which should properly be treated by an efficient technique. Furthermore, it is containing some chemicals obtained from several sources such as H3PO4 (from hydration section), NaOH (from neutralization section) and citric acid (from nickel removal section). The conventional techniques cannot efficiently treat it which is full of COD. Therefore, the electro-Fenton process as a rapid, compact and efficient one has been encouraged to be applied. For this purpose, 47 experiments were designed and carried out using iron electrodes to evaluate the effects of five significant independent variables such as reaction time (min), pH, current density (mA/cm2), volume ratio of H2O2/wastewater (ml/l) and H2O2/Fe2+ molar ratio on the COD removal. Response surface methodology (RSM) was employed to assess individual and interactive effects of the parameters. The optimum conditions were experimentally obtained at reaction time of 87.33 min, pH of 3.03, current density of 57 mA/cm2, H2O2/wastewater volume ratio of 2.13 ml/l and H2O2/Fe2+ molar ratio of 3.61 for COD removal of 62.94 %.

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