Comparing the Effects of Types of Electrode on the Removal of Multiple Pharmaceuticals from Water by Electrochemical Methods

• Published in: Water (Basel) Vol. 12; no. 9; p. 2332
• Main Authors: Liu, Yu-Jung, Huang, Yung-Ling, Lo, Shang-Lien, Hu, Ching-Yao
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2020
• Subjects: Adsorption; Aluminum; Anti-inflammatory agents; Antibiotics; Atenolol; Bubbles; Chloride; Chromatography; Coagulation; Diclofenac; Diffusion rate; electro-coagulation; electro-oxidation; Electrochemistry; Electrodes; Electrolytes; Electrostatic properties; Experiments; Graphite; Inflammation; Ligands; Nonsteroidal anti-inflammatory drugs; nonsteroidal anti-inflammatory drugs (NSAIDs); Oxidation; Oxidation process; Pharmaceuticals; Pollutants; Sulfamethoxazole; sulfonamide antibiotics; Sulfonamides; Wastewater; β-blockers; Japan
• ISSN: 2073-4441; 2073-4441
• DOI: 10.3390/w12092332

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.