Selenium removal from petroleum refinery wastewater using an electrocoagulation technique

• Published in: Journal of hazardous materials Vol. 364; pp. 78 - 81
• Main Authors: Hansen, Henrik K., Peña, Sebastián Franco, Gutiérrez, Claudia, Lazo, Andrea, Lazo, Pamela, Ottosen, Lisbeth M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-02-2019
• Subjects: Current density; Electrocoagulation; Iron hydroxides; Oxidizing medium; Selenium; Iron hydroxides; Electrocoagulation; Selenium; Oxidizing medium; Current density
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2018.09.090

•Electrocoagulation (EC) of wastewater from a petroleum refinery is a promising tool for removing selenium.•Selenium is removed by adsorption and/or co-precipitation with iron hydroxides.•Current density has crucial importance for the removal efficiency.
In the present work, an electrocoagulation technique was tested as a possible technological alternative for the treatment of selenium in wastewater from a petroleum refinery. For this purpose, a batch airlift reactor with air stirring was used. The sacrificial electrodes were made of iron to generate the necessary ferrous ions for the process. The results indicated a selenium removal of 90% from the wastewater after 6 h of treatment, achieving a decrease in concentration from 0.30 mg L−1 to 0.03 mg L−1. The current density was found to be an important variable for the process. In conclusion, the electrocoagulation process seems to be a feasible selenium removal technique applied to petroleum refinery wastewater.