Electrocoagulation in a fixed bed reactor – Color removal in batch and continuous mode

• Published in: Separation and purification technology 2020-12, Vol.253, p.117481, Article 117481
• Main Authors: Rodrigues, Aline R., Seki, Carolina C., Ramalho, Luana S., Argondizo, Alexandre, Silva, Alessandra P.
• Format: Article
• Language: English
• Subjects: Dye removal; Electrocoagulation; Fixed bed; Particulate anode; Textile wastewater
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2020.117481

[Display omitted] •A novel design of electrocoagulation flow reactor with a fixed bed anode.•Batch and continuous operation modes were tested.•Dye removal efficiency of ≈ 98% was achieved with residence time of 0.2 min. In this study, a new design of an electrocoagulation flow reactor, with a fixed bed anode, was used to remove the color of an effluent. The reactor was operated in both batch and continuous mode. In batch operation, the study focused on the effect of the material of the particles (Steel or Al), the applied current and the initial pH of the electrolytic solution over color removal efficiency (Erem) and energy consumption (EC/g). It was observed that the highest values of Erem were reached (>95%) when using pH 3, 6 A and steel particles, with an operating time of less than 5 min. In all conditions of initial pH and current, the lowest values of energy consumption (EC/g) were obtained using steel particles. When operating in continuous mode, the evaluated variables were the initial pH of the solution, the flow rate and the current, and the use of particulate anode (steel particles) was compared with planar anode. Assuming a minimum value of 90% for Erem the lowest value for EC/g (9.7 W h g−1) was obtained using particulate anode, initial pH 3, current of 3 A, and the flow rate of 24 Lh−1, with an Erem of 98%. Comparing this result with the best results from other studies, the removal efficiency was equally high, the EC/g was comparable, but with residence time at least 10 times lower.