Treatment of soluble coffee industrial effluent by electro-coagulation–electro-oxidation process: multiobjective optimization and kinetic study

Author(s):  
I. Dobrosz-Gómez ◽  
M. Á. Gómez-García
2018 ◽  
Vol 5 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Zabihollah Yousefi ◽  
Ali Zafarzadeh ◽  
Abdolaziz Ghezel

Background: Electro-oxidation is developed as an electrochemical method to overcome the problems of the conventional decolorization technologies and is an appropriate alternative for the treatment of colored wastewater from various industries. The purpose of this study was to evaluate the efficiency of the electrochemical oxidation process in removal of chemical oxygen demand (COD) and Acid Red 18 (AR18) dye from aqueous solutions. Methods: In this research, a laboratory scale of electro-coagulation reactor for the treatment of synthetic wastewater was made and studied. The effects of different variables including pH, current density, dye concentration, and electrolysis time were investigated. The experiment steps were designed by DesignExpert 10 software using the selected variables. Finally, the dye and COD analysis was performed by spectrophotometer. The optimization was performed using Taguchi fractional factorial design during the removal of dye and COD. Results: Maximum removal of dye (89%) and COD (72.2%) were obtained at pH=3, current density=20 mA/cm2 , initial dye concentration=100 mg/L, and reaction time=45 min. ANOVA test showed a significant relationship between statistical model and test data. Also, the results indicate that the distribution of the residues of the model was normal. Conclusion: By designing experiments through Taguchi method, the removal process will be optimized and by decreasing the number of experiments, the optimal conditions for pollutant removal will be prepared. The results suggest that the Electro-oxidation system is a very suitable technique for the enhancement of wastewater treatment.


2021 ◽  
Vol 874 ◽  
pp. 155-164
Author(s):  
Herlina ◽  
Muhammad Ali Zulfikar ◽  
Buchari

Recently, the increased use of antibiotics in the environment has been studied and one of them is amoxicillin. Amoxicillin (AMX) is a pharmaceutical product that can become waste due to the continuous use and released into the ecosystem even at low concentrations. The electro-oxidation process is one of the electrochemical methods used to destruct the existence of antibiotics because the process is relatively fast and inexpensive. Platinum electrode and platinum modified cobalt electrodes are used for amoxicillin electro-oxidation at the pH of 2 - 7. The range of this amoxicillin's pH was achieved by the pKa's values of the amoxicillin and measured using a UV/Vis spectrophotometer. Electron transfer during the amoxicillin electro-oxidation process with these electrodes is measured by linear sweep voltammetry. The results obtained during the electro-oxidation process showed that electron transfer of amoxicillin was 1, with a Nernstian factor of 0.0521 V/pH for platinum electrode and platinum modified cobalt electrodes, Pt/Co(OH)2 and Pt/Co respectively with values of 0.0506 V/pH and 0.0673 V/pH.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2332
Author(s):  
Yu-Jung Liu ◽  
Yung-Ling Huang ◽  
Shang-Lien Lo ◽  
Ching-Yao Hu

Considering the lack of information on simultaneously removing multiple pharmaceuticals from water or wastewater by electrochemical methods, this study aimed to investigate the removal of multiple pharmaceuticals by electro-coagulation and electro-oxidation based on two types of electrodes (aluminum and graphite). The synthetic wastewater contained a nonsteroidal anti-inflammatory drug (diclofenac), a sulfonamide antibiotic (sulfamethoxazole) and a β-blocker (atenolol). The pharmaceutical removal with electro-oxidation was much higher than those with the electro-coagulation process, which was obtained from a five-cell graphite electrode system, while the removal of pharmaceuticals with aluminum electrodes was about 20% (20 µM). In the electro-coagulation system, pharmaceutical removal was mainly influenced by the solubility or hydrophilicity of the compound. In the electro-oxidation system, the removal mechanism was influenced by the dissociation status of the compounds, which are attracted to the anode due to electrostatic forces and have a higher mass transformation rate with the electro-oxidation process. Therefore, atenolol, which was undissociated, cannot adequately be eliminated by electro-oxidation, unless the electrode’s surface is large enough to increase the mass diffusion rate.


2020 ◽  
Vol 50 (2) ◽  
pp. 217-230 ◽  
Author(s):  
Izabela Dobrosz-Gómez ◽  
Miguel Ángel Gómez García ◽  
Guillermo H. Gaviria ◽  
Edison GilPavas

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