Raw landﬁll leachate treatment using an electrocoagulation process with a novel rotating electrode reactor Ahmed Samir Naje, Mohammed A. Ajeel, Isam Mohamad Ali, Hussein A. M. Al-Zubaidi and Peter Adeniyi Alaba ABSTRACT In this work, landﬁll leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The inﬂuence of rotating anode speed on the removal efﬁciency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landﬁll leachate was investigated. The inﬂuence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance. Ahmed Samir Naje Collage of Water Resource Engineering, AL-Qasim Green University, Babylon 51031, Iraq Mohammed A. Ajeel (corresponding author) Department of Environmental and Energy, Al-Karkh University of Science, Baghdad, Iraq E-mail: mohamed_motari@yahoo.com Isam Mohamad Ali Karbala Technical Institute Al-Furat Al-Awsat Technical University Karbala, Iraq Hussein A. M. Al-Zubaidi Department of Environmental Engineering, College of Engineering, University of Babylon, Babylon, Iraq Peter Adeniyi Alaba Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia Key words | electrocoagulation, impeller, landﬁll leachate, rotating electrode INTRODUCTION The continuous increase in the human population and the changes in lifestyle have led to a huge amount of solid waste pollutant, which causes an unpleasant environmental impact and resources depletion (Azni ). Even though many techniques have been adopted to overcome the solid waste pollution problem such as recycling and reuse, the landﬁlling process is the main method adopted for the dispo- sal of solid waste. However, the production of leachate from landﬁlling is the main drawback of this method and it has become a serious threat to the environment. Landﬁll lea- chate is a complex combination pollutant consisting of heavy metals, and organic and inorganic substrate. Some of these materials are toxic and refractory pollutants (Van der Bruggen et al. ). It is well known that biological treatment is the cheapest technique for wastewater treatment. However, the presence of the toxic refractory pollutants (non-biodegradable organic pollutants) in landﬁll leachate reduces the performance of this technique (Naje et al. ). Selection of a suitable method for landﬁll leachate treatment basically depends on the composition of the leachate. Various techniques have been attempted for treatment of landﬁll leachate, including adsorption, electro-oxidation, biological, and advanced oxidation. Most of these techniques suffer certain drawbacks. For instance, the adsorption method is a very slow process with low efﬁciency (Hassani et al. ); the electrochemical oxidation process is selective and suffers from the electrode passivation phenomenon; and the 458 © IWA Publishing 2019 Water Science & Technology | 80.3 | 2019 doi: 10.2166/wst.2019.289 Downloaded from http://iwaponline.com/wst/article-pdf/80/3/458/620810/wst080030458.pdf by guest on 22 September 2022