Effect of presence of chemical species on removal of phenol in electrocoagulation process

Abstract

Effect of the presence of chemical species, namely, NaHCO₃, CaSO₄, MgSO₄, and MgCl₂, on the performance of electrocoagulation (EC) process when treating synthetic phenolic wastewater was investigated. The investigation was performed using individual and combinations of two, three, and four species. Chemical species, under investigation, were added to phenol solution that was prepared using distilled water. Additionally, effects of operational parameters, namely, initial phenol concentration, current density, and supporting electrolyte (NaCl) concentration on the process performance was also studied using phenol solution that was prepared using tap water. The results showed that presence of chemical species such as bicarbonates and sulfates have negative effects on the performance of EC process. Removal efficiency of phenol was found to decrease with respect to time when CaSO₄, MgSO₄, and NaHCO₃ were added to phenol solution. As an example, when only CaSO₄ was added to the solution, more than 30% of phenol remained in solution after 10 min of investigation, while complete removal of phenol was achieved after 2 min when chemical species under investigation were not added. The results also showed that addition of more species resulted in more reduction of phenol removal efficiency. When CaSO₄ and MgSO₄ were added to the solution, 35% of phenol remained in solution after 10 min of treatment period.

Keywords:

• Steel electrodes
• Adsorption
• Current density
• Supporting electrolyte
• Phenol concentration

Aknowledgment

The authors would like to express their gratitude to King Fahd University of Petroleum and Minerals for the technical support provided during the investigation period.