Removal of Phenol from Aqueous Solution by Coupling Alternating Current with Biosorption

Abstract

This work suggested a new alternative for the acceleration of pollutants removal by adopting alternating current (AC) in the treatment of phenol. A comparative study between the electrocoagulation (EC) using two aluminum electrodes and coupling AC with biosorption was achieved. Tunisian Luffa Cylindrica (L.C) and hybrid material (Luffa Cylindrica (L.C) +4% Zn²⁺) synthesized by precipitation method under AC were chosen for the biosorption. A series of assays were undertaken to assess the effect of the experimental parameters such as pH, initial concentration, inter-distance, electrodes material, voltage, current density, and salts. The evolution of chemical oxygen demand (COD), total organic carbon (TOC), and phenol removal was performed. The biosorption kinetic tests were performed based on the fractal Brouers–Sotolongo (B.S) model. The results demonstrated the effect of coupling AC with biosorption on the pollutants removals compared to the EC process. An increase in the % phenol COD and TOC removals was observed. The percentages of COD removal by the EC and the coupling processes reached respectively 66.4, 77, and 86.6% when using pure the L.C and L.C + 4% Zn²⁺. While the percentages of TOC removals reached respectively 81.6, 90.1, and 93.9% when adopting the same processes and using the same biosorbents after a required time of 180, 120, and 90 min. The evaluation of the quality of the treated water was carried out based on COD, TOC removals, and the germination index. The phytotoxicity test confirmed the possibility of the treated water reuse.