ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Performance investigation of electrocoagulation and Electro-Fenton processes for high strength landfill leachate: operational parameters and kinetics

L. C. Ling, Archina Buthiyappan, Abdul Aziz Abdul Raman, Noorul Huda Abdul Jabar, and Ramesh Singh

Department of Chemical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia

E-mail: azizraman@um.edu.my

Received: 27 June 2021  Accepted: 28 December 2021

Abstract:

Leachate landfills contain significant amounts of heavy metals, organic pollutants, inorganic salts, ammonia nitrogen, and chlorinated organics, which negatively influence the environment. Therefore, it is a must to treat them before being released into the environment efficiently. This study investigated the effectiveness of batch Electrocoagulation (EC) and Electro-Fenton (EF) processes to treat the high-strength landfill leachate. The effect of operating parameters, including initial pH of the leachate, contact time, and a mass ratio of COD: H₂O_2, was investigated on the removal efficiencies of chemical oxygen demand (COD) and color from leachate. The result shows that, under the optimal pH 6 and reaction time of 17.5 min, EC achieved COD and color removal of 66.2% and 94.4%, respectively. However, EF obtained a higher COD removal of 69.8% and 88.1% of color removal at pH of 9 and COD: H₂O₂ Ratio of 9.5 within 6.7 min. The result revealed that both processes are reported to remove more than 80% color. However, EF obtained a higher degradation rate than EC. Besides, the EF process also generated 47.4% less sludge than the EC process under the optimal conditions. Cost estimation indicates that EF is less expensive (0.48 USD) than electrocoagulation (0.75 USD). In summary, Electro-Fenton is a more reliable, cost-effective, and energy-efficient method of removing landfill leachate than electrocoagulation, requiring less treatment time and producing less sludge.

Keywords: Landfill leachate; Electrocoagulation; Electro-Fenton; Cost estimation; Sludge; Iron electrode

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-02052-5

Chemical Papers 76 (5) 2991–3003 (2022)