COD removal from leachate by electrocoagulation process: treatment with monopolar electrodes in parallel connection

Abstract This study examines the removal of chemical oxygen demand (COD) from landfill leachate generated from the municipal landfill site of Bingol, Turkey. The effect of parameters such as current density, pH, and inter-electrode distance during the electrocoagulation (EC) process on COD removal of the process was investigated. Moreover, for COD removal, the energy consumption and operating costs were calculated for iron electrode under the EC conditions. COD removal efficiency was 72.13% at the current density of 16 mA m−2, pH of 8.05, and the inter-electrode distance of 9 mm at the detention time of 60 min with iron electrode and the COD concentration was reduced from 6,100 mg L−1 to 1,700 mg L−1 by EC. The highest value of the electrical energy and electrode consumptions per kg of COD in the optimum conditions were determined as 0.055 kWh kg−1 COD and 3.43 kg kg−1 COD and the highest operating cost value was found to be 1.41 US$ kg−1 COD for 0–60 min time intervals.

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Optimizing electrocoagulation process using experimental design for COD removal from unsanitary landfill leachate

Water Science & Technology ◽

10.2166/wst.2017.460 ◽

2017 ◽

Vol 76 (11) ◽

pp. 2907-2917 ◽

Cited By ~ 4

Author(s):

Aysenur Ogedey ◽

Mehtap Tanyol

Keyword(s):

Current Density ◽

Landfill Leachate ◽

Oxygen Demand ◽

Cod Removal ◽

Main Process ◽

Electrode Distance ◽

Electrocoagulation Process ◽

High Pollution ◽

Pre Treatment ◽

Treatment Step

Abstract Leachate is the most difficult wastewater to be treated due to its complex content and high pollution release. For this reason, since it is not possible to be treated with a single process, a pre-treatment is needed. In the present study, a batch electrocoagulation reactor containing aluminum and iron electrodes was used to reduce chemical oxygen demand (COD) from landfill leachate (Tunceli, Turkey). Optimization of COD elimination was carried out with response surface methodology to describe the interaction effect of four main process independent parameters (current density, inter-electrode distance, pH and time of electrolysis). The optimum current density, inter-electrode distance, pH and time of electrolysis for maximum COD removal (43%) were found to be 19.42 mA/m2, 0.96 cm, 7.23 and 67.64 min, respectively. The results shown that the electrocoagulation process can be used as a pre-treatment step for leachate.

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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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Investigating the Electrocoagulation Treatment of Landfill Leachate by Iron/Graphite Electrodes: Process Parameters and Efficacy Assessment

Water ◽

10.3390/w14020205 ◽

2022 ◽

Vol 14 (2) ◽

pp. 205

Author(s):

Tahereh Rookesh ◽

Mohammad Reza Samaei ◽

Saeed Yousefinejad ◽

Hassan Hashemi ◽

Zahra Derakhshan ◽

...

Keyword(s):

Current Density ◽

Landfill Leachate ◽

Performance Indicators ◽

Oxygen Demand ◽

Cost Effective ◽

Leachate Treatment ◽

Graphite Electrodes ◽

Electrode Distance ◽

Electrocoagulation Process ◽

Efficacy Assessment

Electrocoagulation is a widely used method for treating leachate since it is cost effective and eco-friendly. In the present study, the electrocoagulation process was employed to remove chemical oxygen demand (COD), NH4+, total dissolved solids (TDS), total suspended solids (TSS), turbidity, and color from landfill leachate. At first, lime was used as a pretreatment, then the Fe/Gr and Ti/PbO2/steel electrodes were used, and the optimum electrode was selected. Afterwards, the effects of some variables, including pH, current density, temperature, the inter-electrode distance, and the type of electrolyte were investigated. Results showed that COD, NH4+, TSS, TDS, electrical conductivity (EC), turbidity, color, and pH of effluent pretreatment chemical reached 22,371, 385, 884, 21,820 (mg/L), 13.8 (ms/cm3), 1355 (NTU), 8500 (TCU) and 10, respectively (the removal efficiency was 0, 20.37, 32.4, 61.99, 59.18, and 56.6 percent). With the Fe/Gr electrode, the optimal condition was observed as follows: pH of 7.5, current density of 64 mA/cm2, inter-electrode distance was equal to 1.5 cm, temperature at 20 °C, and retention time 2–4 h. Overall, the electrocoagulation with the Fe/Gr electrode was a suitable technology for landfill leachate treatment due to its effectiveness for the removal of both COD and NH4+, with advantageous performance indicators.

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Electrochemical treatment and operating cost analysis of textile wastewater using sacrificial iron electrodes

Water Science & Technology ◽

10.2166/wst.2009.672 ◽

2009 ◽

Vol 60 (9) ◽

pp. 2261-2270 ◽

Cited By ~ 38

Author(s):

M. Kobya ◽

E. Demirbas ◽

A. Akyol

Keyword(s):

Current Density ◽

Batch Reactor ◽

Operating Cost ◽

Oxygen Demand ◽

Textile Wastewater ◽

Iron Electrode ◽

Treated Wastewater ◽

Experimental Conditions ◽

Potential Measurement ◽

Initial Ph

Electrocoagulation (EC) method with iron electrode was used to treat the textile wastewater in a batch reactor. Iron electrode material was used as a sacrificial electrode in monopolar parallel mode in this study. The removal efficiencies of the wastewater by EC were affected by initial pH of the solution, current density, conductivity and time of electrolysis. Under the optimal experimental conditions (initial pH 6.9, current density of 10 mA/cm2, conductivity of 3,990 μS/cm, and electrolysis time of 10 min), the treatment of textile wastewater by the EC process led to a removal capacity of 78% of chemical oxygen demand (COD) and 92% of turbidity. The energy and electrode consumptions at the optimum conditions were calculated to be 0.7 kWh/kg COD (1.7 kWh/m3) and 0.2 kgFe/kg COD (0.5 kgFe/m3), respectively. Moreover, the operating cost was calculated as 0.2 €/kg removed COD or 0.5 €/m3 treated wastewater. Zeta potential measurement was used to determine the charge of particle formed during the EC which revealed that Fe(OH)3 might be responsible for the EC process.

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Raw landfill leachate treatment using an electrocoagulation process with a novel rotating electrode reactor

Water Science & Technology ◽

10.2166/wst.2019.289 ◽

2019 ◽

Vol 80 (3) ◽

pp. 458-465 ◽

Cited By ~ 3

Author(s):

Ahmed Samir Naje ◽

Mohammed A. Ajeel ◽

Isam Mohamad Ali ◽

Hussein A. M. Al-Zubaidi ◽

Peter Adeniyi Alaba

Keyword(s):

Landfill Leachate ◽

Suspended Solids ◽

Treatment Process ◽

Oxygen Demand ◽

Neutral Medium ◽

Leachate Treatment ◽

Rotating Speed ◽

Electrode Distance ◽

Treatment Performance ◽

Electrocoagulation Process

Abstract In this work, landfill leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The influence of rotating anode speed on the removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landfill leachate was investigated. The influence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance.

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

Journal of Water Supply Research and Technology—AQUA ◽

10.2166/aqua.2020.109 ◽

2020 ◽

Vol 69 (4) ◽

pp. 345-354 ◽

Cited By ~ 1

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.

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Electrochemical Treatment of Oilfield Produced Wastewater on Ni-Sb- SnO2/Ti Electrodes

Journal of Advanced Oxidation Technologies ◽

10.1515/jaots-2013-0209 ◽

2013 ◽

Vol 16 (2) ◽

Author(s):

Wang Yun-Hai ◽

Kuang Jun-Yao

Keyword(s):

Energy Efficiency ◽

Current Efficiency ◽

Current Density ◽

Tin Dioxide ◽

Electrochemical Treatment ◽

Cod Removal ◽

Electrolysis Time ◽

Removal Ratio ◽

Electrode Distance

AbstractNickel and antimony doped tin dioxide (NATO) coated titanium electrodes were used for electrochemical treatment of oilfield produced wastewater. The effects of electrode distance, current density and electrolysis time on COD removal ratio, current efficiency, energy efficiency and BOD to COD ratio were investigated. The optimized electrode distance of 5 mm and current density of 6 mA cm

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Application of Doehlert design for optimization of the electroflotation method for the treatment of wastewater from poultry slaughtering and processing

Research Society and Development ◽

10.33448/rsd-v9i12.10556 ◽

2020 ◽

Vol 9 (12) ◽

pp. e11491210556

Author(s):

Mariana Lopes Bastos ◽

Joel Marques da Silva ◽

Silvânio Silvério Lopes da Costa ◽

Joel Alonso Palomino-Romero

Keyword(s):

Current Density ◽

Treatment Time ◽

Operating Cost ◽

Oxygen Demand ◽

Operating Conditions ◽

Optimum Process ◽

Process Conditions ◽

Doehlert Design ◽

Density Treatment ◽

Suitable Process

In this work, an electroflotation (EF) method for the treatment of poultry slaughterhouse effluent was proposed, and its efficiency in reducing chemical oxygen demand (COD) was investigated. The following operating conditions were optimized through Doehlert design: [Al2(SO4)3], pH, treatment time, and current density. Treatment of the effluent was carried out in a reactor with TiO2–RuO2 (anode) and iron (cathode) electrodes. The optimum process conditions were obtained with a pH 9, current density of 60 A m–2, electrolysis time of 80 min, and [Al2(SO4)3] of 1.8 mg L–1. Under these operating conditions, turbidity, COD, and biochemical oxygen demand (BOD) removal efficiencies of 93.1%, 80.7%, and 89.7%, respectively, were obtained. The operating cost of the process was calculated at 0.9 USD per m³. The EF method combined with chemical coagulation was shown to be a suitable process for the treatment of effluent from the slaughter and processing of poultry.

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Optimization of electrocoagulation process parameters for enhancing phosphate removal in a biofilm-electrocoagulation system

Water Science & Technology ◽

10.2166/wst.2021.132 ◽

2021 ◽

Author(s):

Jie Zeng ◽

Min Ji ◽

Yingxin Zhao ◽

Pedersen ◽

Thomas Helmer ◽

...

Keyword(s):

Reaction Time ◽

Removal Efficiency ◽

Operating Cost ◽

Integrated System ◽

Phosphate Removal ◽

Electrode Distance ◽

Electrocoagulation Process ◽

Biofilm Process ◽

Switching Mode ◽

The Individual

Abstract This study aimed to enhance the removal of phosphate in synthetic rural sewage by using a continuous electrocoagulation combined with biofilm process in an integrated system. Characteristic indexes of biofilm process effluent covering pH, DO, SS, COD and phosphate maintained a narrow fluctuation range and tended not readily to influence the phosphate removal of subsequent electrocoagulation. Three parameters including inter-electrode distance, current intensity and reaction time were selected to investigate the performance of enhancing phosphate removal. On the strength of single-factor tests, the Box-Behnken design (BBD) coupled with response surface methodology (RSM) was applied to investigate the individual and mutual interaction impacts of the major operating parameters and to optimize conditions. The optimum conditions were found to be inter-electrode distance of 1.8 cm, current density of 2.1 mA/cm2 and EC reaction time of 34 min, and the phosphate removal efficiency was achieved to be 90.24% along with less than 1 mg/L in case of periodic polarity switching mode, which raised removal efficiency by 10.10% and reduced operating cost by 0.13 CNY/g PO4− compared to non-switching mode. The combination of biofilm processing and electrocoagulation treatment was proven a valid and feasible method for enhancing phosphate removal.

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Domestic wastewater treatment by real-scale electrocoagulation process

Water Science & Technology ◽

10.2166/wst.2020.128 ◽

2020 ◽

Vol 81 (4) ◽

pp. 656-667 ◽

Cited By ~ 1

Author(s):

Serdar Koyuncu ◽

Sema Arıman

Keyword(s):

Wastewater Treatment ◽

Operating Cost ◽

Treatment Plant ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Urban Wastewater ◽

Electrocoagulation Process ◽

Removal Efficiencies ◽

Urban Wastewater Treatment ◽

Real Scale

Abstract In this study, domestic wastewaters originating from a settlement with a population of 17,500 were treated by electrocoagulation process in a real-scale EC plant and the economic applicability of the process was investigated. The removal efficiencies of control parameters in the influent and effluent of the real-scale treatment plant such as suspended solids (SS), biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and changes of pH and conductivity parameters were monitored for 12 months. The obtained data were evaluated according to European Urban Wastewater Treatment Directive, Turkish Water Pollution Control Regulation and Turkish Urban Wastewater Treatment Regulation. According to the results obtained, the removal efficiencies of the pollutant parameters were achieved in the range of 72–83% for SS, 67–80% for COD, 69–81% for BOD, 21–47% for TN and 27–46% for TP. Considering the Turkish wastewater discharge regulations, it can be concluded that the discharge standards for SS, COD and BOD parameters were achieved while they were not achieved in certain periods for TN and TP. In addition, the energy consumption and the operating cost of this real-scale plant were determined to be 0.49–0.54 kWh/m3 and 0.24–0.28 EUR/m3, respectively.

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