Removal of bromide from raw water in drinking industry by electrochemical method with horizontal rotating anode reactor

• Published in: Desalination and water treatment 2021-05, Vol.223, p.200-207
• Main Authors: Mukimin, Aris, Zen, Nur, Vistanty, Hanny, Nilawati
• Format: Article
• Language: English
• Subjects: Bromate; Bromide; Horizontal rotating drum electrocatalytic reactor reactor; Microporous layer carbon cloth; Pt-carbon cloth
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2021.27131

Drinking water industries in Indonesia generally use the ozonation method as a disinfection process (more than 90%). However, it has a negative effect in oxidizing bromide (Br–) into bromate, which is a carcinogenic compound associated with several clinical symptoms, such as nausea, vomit and even kidney failure. Meanwhile, bromide anion is thermodynamically easy to be oxidized into bromine (Eo: 1.074 V), resulting in an effective removal of bromide. A double-chamber electrocatalytic reactor with a working volume of 100 L was made with platinum-doped carbon cloth, copper, and proton exchange membrane as anode, cathode, and separator, respectively. The reactor was designed as a horizontal rotating drum electrocatalytic reactor which will accelerate the oxidation of Br–/Br2 and enhance the transfer rate of Br2 from liquid to gas phase. Potential, flowrate, anode rotation speed and salt concentration were chosen as evaluated parameters. Bromide concentration of 0.3858 mg/L was significantly reduced (93%) at 8.7 L/min flowrate, 7 V potential, 2.3 A current, and 100 mg/L salt concentration. Raw water containing 0.3858 mg/L of bromide, which resulted in 0.3 mg/L bromate after ozonation and reduced to 0.002 mg/L and was able to meet the requirements of SNI 3553 or 6241. Total energy consumption to remove bromide was about 8.17 kJ/g Br or 1.2 IDR/L raw water.