scholarly journals Application of Electrocoagulation Process Using Iron and Aluminum Electrodes for Fluoride Removal from Aqueous Environment

2012 ◽  
Vol 9 (4) ◽  
pp. 2297-2308 ◽  
Author(s):  
Edris Bazrafshan ◽  
Kamal Aldin Ownagh ◽  
Amir Hossein Mahvi

Fluoride in drinking water above permissible level is responsible for human being affected by skeletal fluorosis. The present study was carried out to assess the ability of electrocoagulation process with iron and aluminum electrodes in order to removal of fluoride from aqueous solutions. Several working parameters, such as fluoride concentration, pH, applied voltage and reaction time were studied to achieve a higher removal capacity. Variable concentrations (1, 5 and 10 mg L-1) of fluoride solutions were prepared by mixing proper amount of sodium fluoride with deionized water. The varying pH of the initial solution (3, 7 and 10) was also studied to measure their effects on the fluoride removal efficiency. Results obtained with synthetic solution revealed that the most effective removal capacities of fluoride could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 10-40 V, enhanced the treatment rate. Also comparison of fluoride removal efficiency showed that removal efficiency is similar with iron and aluminum electrodes. Finally it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of fluoride from water and wastewater.

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
M. Behbahani ◽  
M.R. Alavi Moghaddam ◽  
M. Arami

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.


Author(s):  
Davoud Balarak ◽  
Kethineni Chandrika ◽  
Marzieh Attaolahi

In this study, efficiency of electrocoagulation (EC) process with aluminum electrodes for treatment of Amoxicillin (AMO) from synthetic solution has been studied and concluded. This experiment was conducted in a batch system with a volume of 1 L that had been equipped with four aluminum electrodes. The effect of operating parameters, such as voltage, time of reaction, initial AMO concentration, KCl concentration and pH on the AMO removal efficiency was investigated. In optimum condition (pH 7, voltage 60 V, electrolysis time 75 min, KCl concentration 3 g/L), electrocoagulation method was able to remove 98.8% of AMO antibiotics from synthetic solution.  In addition, it is found that an increase in the applied voltage the speed of the treatment significantly. However, simultaneous increase of electrode and energy consumption was observed. The method was found to be highly efficient and relatively fast compared to conventional existing techniques and also, it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of AMO from water and wastewater.


2012 ◽  
Vol 27 ◽  
pp. 61-66 ◽  
Author(s):  
Kedar Nath Ghimire

Removal of fluoride is investigated onto several metal ions loaded phosphorylated orange juice residue and commercially available alumina. The experimental results revealed that cerium (IV) loaded phosphorylated orange waste indicated excellent fluoride removal efficiency at acidic pH range and while that lanthanum loaded at neutral pH range. Both the metal loaded adsorbents are found superior to the commercially available activated alumina.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6660 J. Nepal Chem. Soc., Vol. 27, 2011 61-66 


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3343
Author(s):  
Bo Yang ◽  
Guirong Sun ◽  
Bingxu Quan ◽  
Jiawei Tang ◽  
Chunhui Zhang ◽  
...  

The emerging interest in fluoride-removal from wastewater has attracted attention to zeolite since it has been considered as a natural adsorbent. However, the fluoride-removal efficiency of natural zeolite is generally low. As part of the effort to improve the zeolite adsorption efficiency, we have produced and tested the Mn-Ti modified zeolite. In the current work, the material preparation is discussed, and prepared materials were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy, and Fourier transform infrared (FTIR) spectra. Both static and dynamic experiments were conducted to examine the effects of independent variables. In the static adsorption section, sensitivity analysis experiments were conducted for independent variables, such as adsorbent dosage, pH, temperature, and competitive ions. The maximum adsorption capacity is 2.175 mg/g, which was obtained at PH = 7, temperature = 25 °C, and initial fluoride concentration = 10 mg/L. For adsorption kinetics, both Lagergren and Pseudo-second order models predict the experiments very well, which probably demonstrates that the current process is a combination of physical sorption and chemisorption. For adsorption isotherms, the Freundlich model performs better than the Langmuir model since it is usually applied to illustrate adsorption on inhomogeneous surfaces. In the dynamic adsorption section, sensitivity analysis experiments were also conducted for independent variables, such as adsorbent thickness, flow velocity, initial fluoride concentration, and PH. Additionally, the adsorption mechanism is also discussed. The main reason is the hydrated metal fluoride precipitate formation. As we know, the current work provides the first quantified comparison of the natural zeolite and the Mn-Ti modified zeolite regarding fluoride-removal efficiency.


2020 ◽  
Vol 20 (3) ◽  
pp. 536
Author(s):  
Nurulhuda Amri ◽  
Ahmad Zuhairi Abdullah ◽  
Suzylawati Ismail

This work compares commercial aluminium electrode for use in the treatment of wastewater by electrocoagulation process against waste aluminium cans electrode. The applicability of the waste aluminium cans electrode was tested for decolorization of Acid Red 18 dye as a model pollutant. The batch electrocoagulation process using both types of electrode was conducted at a current density of 25 mA/cm2, a pH of 3, an initial concentration of 100 mg/L and 25 min of reaction time. The elemental composition and surface morphology of both electrode materials and the sludge produced were analyzed using SEM-EDX to establish the correlation between the properties and characteristics of both electrode materials with their dye removal performance. The results demonstrated that waste aluminium cans performed better than commercial aluminium electrode with a removal efficiency of 100% in 25 min of reaction time. This was due to the higher Al dissolution of waste aluminium cans electrode that contributed to the larger amount of Al3+ released into the solution to consequently form more flocs to remove the dye molecules. In conclusion, the proposed waste aluminium electrode was considered as efficient and cost-effective and had the potential to replace the conventional ones in treating colored industrial wastewater using electrocoagulation process.


2019 ◽  
Vol 26 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Mohammed Alameen Salem ◽  
Najwa Majeed

Cadmium is one of the heavy metal found in the wastewater of many industries. The electrocoagulation offers many advantages for the removal of cadmium over other methods. So the removal of cadmium from wastewater by using electrocoagulation was studied to investigate the effect of operating parameters on the removal efficiency. The studied parameters were the initial pH, initial concentration, and applied voltage. The study experiments were conducted in a batch reactor with  with two pairs of aluminum electrodes with dimension  and 2mm in thick with 1.5 cm space between them. The optimum removal was obtained at pH =7, initial concentration = 50 mg/L, and applied voltage = 20 V and it was 90%.


Author(s):  
Nuno S. Graça ◽  
Ana M. Ribeiro ◽  
Alírio E. Rodrigues

Abstract An artificial neural network (ANN) with the topology 8-94-85-2 (input – hidden layer 1 - hidden layer 2 - output) was used to model the operation of the continuous electrocoagulation (CEC) process for the removal of fluoride from water. After the ANN training, the sum of the squared errors (MSE) and the determination coefficient (R2) of the testing set model predictions were 0.0088 and 0.999, respectively, showing a good generalization and model's predictive capacity. The optimization of the process cost using the genetic algorithm (GA) showed that the optimal conditions are highly dependent on the feed concentration and the fluoride removal requirements. For a 5 L of water containing 10 mg/L of fluoride, the optimal conditions to reduce the fluoride concentration below the permissible limit (1.5 mg/L) are 88.3 mA of current intensity, a flow rate of 73.6 mL/min, and the use of a series monopolar (SM) electrode configuration, corresponding to a fluoride removal of 85% and an operating cost of 0.05 €/L.


2020 ◽  
Vol 10 (2) ◽  
pp. 171-184
Author(s):  
Noufissa Sqalli ◽  
Abdelhafid Essadki ◽  
Essedik Elqars ◽  
Essedik Elqars

This study concerns the ability of electrocoagulation process to remove simultaneously disperse and reactive dyes by using combined iron and aluminum electrodes in bipolar mode. A statistical experiment design (Response Surface Methodology: RSM) was adopted to model the process and to optimize the parameters influencing the removal efficiency of the dyes.  The mathematical model is established, using a rotatable central composite design uniform to study the empirical relationships between two responses (Removal efficiency, energy consumption) and five factors: initial pH, current density, the concentration of supporting electrolyte, time and stirring speed. This treatment, therefore, led to a removal efficiency that can reach more than 95% with low consumption energy of 9 kWh/Kg of removed dye. Kinetic, isotherm adsorption and thermodynamic studies were undertaken with the optimized parameters. Electrocoagulation mechanism was modeled using adsorption kinetics and isotherm models, it is sited were on the insoluble iron and aluminum flocs. This study shows that the Freundlich model fit the adsorption isotherm, the kinetic of the electrocoagulation is better presented by the pseudo- second-order kinetic, the adsorption is endothermic and spontaneous for both dyes. Analysis of the sludge allowed quantifying the role of each electrode in removing dyes.


Author(s):  
Faheem Akhter ◽  
Arsalan A. Jokhio ◽  
Javed A. Noonari

Moringa Oleifera is considered to be a natural bio-adsorbent. Unlike chemical coagulants, Moringa Oleifera seeds are environment friendly with various other advantages. The present study investigated the fluoride removal efficiency of Moringa Oleifera from water. Influence of adsorbent dose (1, 2, 4 g/L), contact time (20, 40 and 60 min) and initial fluoride concentration (2 and 5 mg/L) over removal efficiency were determined and optimized. It was found that increased adsorbent dose and contact time enhanced the removal efficiency which is in agreement with the previous studies. The highest removal of 88.1% was achieved when the adsorbent dose and contact time were optimized to 4 g/L and 60 minutes with an initial fluoride concentration of 2 mg/L. The results showed that Moringa Oleifera can be used as an environment friendly, cheap and effective bio-adsorbent for fluoride removal from aqueous solution. All the experimental facilities were provided by Bio-Fuel Lab, Energy & Environment Department, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Pakistan. The samples were analyzed at the Pakistan Council of Research in Water Resources (PCRWR), Tando Jam, Pakistan.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Kifle Workeneh ◽  
Enyew Amare Zereffa ◽  
Toshome Abdo Segne ◽  
Rajalakshmanan Eswaramoorthy

Fluoride has become a notable toxicological environmental hazard worldwide because it is often found in groundwater. In the present study, hydroxyapatite adsorbent was synthesized from eggshell waste to remove fluoride from aqueous solution. XRD, FT-IR, and TGA techniques were used to characterize the prepared adsorbent. Batch adsorption studies were performed to examine the adsorption capacity of hydroxyapatite such as the effect of the initial pH of the solution, contact time, adsorbent dose, and initial fluoride concentration. The fluoride ion-selective electrode was used to determine the fluoride removal efficiency. 98.8% of fluoride was removed at pH 3.0, but at pH ~7.0, 85% of fluoride was removed; it shows that the fluoride adsorption is pH dependent. The adsorption isotherm studies (Langmuir and Freundlich models) and the experimental results for the removal of fluoride showed that the Langmuir model was more favorable and the reaction followed pseudo-second-order kinetics. In real water samples, the prepared hydroxyapatite derived from eggshell exhibited 81% removal efficiency. Our results indicate that eggshell waste-derived hydroxyapatite may be an alternative source for defluoridation in developing countries.


Sign in / Sign up

Export Citation Format

Share Document