International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014 Available online at http://www.ijsrpub.com/ijsrk ISSN: 2322-4541; ©2014; Author(s) retain the copyright of this article http://dx.doi.org/10.12983/ijsrk-2014-p0497-0508 497 Review Paper Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes Mostafa Mohammadizaroun, Mohd Suffian Yusoff* School of Civil Engineering, Engineering Campus, University Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia *Corresponding Author: suffian@usm.my Received 28 September 2014; Accepted 11 November 2014 Abstract. The most techniques for treating leachate and wastewater are physical, chemical, biological, advanced oxidation and electrochemical techniques. Developed oxidation techniques lead to high treatment cost and mostly are used in purifying grade waters. Among these techniques, the chemical coagulation technique not only is a slow process, but also produces a large amount of sludge. Electrocoagulation has been used for treating industrial effluent and leachate as a potential technique because of its compatibility and adaptability with environment. In this technique, a direct current source between metal electrodes plunged in the effluent is used to dissolve the electrode plates into the effluent. The metal ions with appropriate pH can create various types of coagulated species and metal hydroxides that in turn cause to rolling up and destabilizing the elements, or catalyzing and absorbing the dissolved pollutants. Therefore, the purpose of the current study is to examine the potentials of electrocoagulation in treating the leachate and wastewater by treating the heavy metals and their colour and salinity. Furthermore, the present study aims to investigate the electrocoagulation, electrochemical technologies and their design and application in treating the leachate, water, and wastewater. This work mostly dealt with the electrocoagulation (EC), electrodeposition, electroflotation (EF), and electrooxidation. It was shown that Electrodeposition is efficient in treating the wastewater stream and removing heavy metals. In addition, electrocoagulation was used for treating wastewater and producing clean water as well. It was also found that using aluminum, iron or the hybrid Al/Fe electrodes are more applicable. Keyword: Electrocoagulation, Treatment, Leachate, Wastewater, Iron and Aluminum Electrode, Hydride electrode 1. INTRODUCTION Electrocoagulation is an electrochemical method that is employed for both wastewater and surface water treatment. In this method, sacrificial anodes are oxidized and active coagulant precursors, such as aluminum or iron cations, are released into liquid. During this process, additional electrolytic reactions produce gas at the cathode, which is usually in the form of hydrogen bubbles (Holt et al., 2005). Drinking water that is polluted by heavy metals is dangerous for human health. One of the techniques that are used for purifying wastewater is Electrocoagulation. This technology employs electrolytic oxidation of anode materials and in-situ generation of coagulation (Wan et al., 2011). The purpose of using electrocoagulation (EC) is removing various types of pollutants such as heavy metal ions from water and wastewater effluents (Shafaei et al., 2010). . electrocoagulation (EC) has attracted the attention of the environmental sectors largely as an efficient way to treat different types of water and wastewater during the last two decades, and especially during the last few years. The purpose of the present work is to study some related researches that were conducted mainly on the widespread use of practical electrocoagulation in treating different types of water and wastewater during 2008-2014. Due to the large amount of wastewater coming from industry and its variety, its purification is still a noteworthy environmental problem in the world (Zodi et al., 2009). Some of these wastewater types can show evidence of high chemical oxygen demand (COD), dark color, and strong bad smell. Thus it is essential to treat the sewerage before discharging them into the environment and water sources. For this purpose, electrocoagulation has been employed to purify different types of wastewater generated by industry section in recent years (Khemis et al., 2006). Accordingly, EC method has absorb the interest of many researchers for being applied to treat the water and wastewater. It is one of the recently developed water technologies that has been used successfully in purifying different types of wastewaters (Tchamango et al., 2010).