Treatment of a Malaysian Leachate Sample Using Electrocoagulation

Abstract

A real leachate sample, taken from a Kuala Lumpur suburban area, was used in order to investigate the efficiency of electrocoagulation using Fe electrodes as both cathodes and anodes to reduce chemical oxygen demand (COD) and color of the sample. The effects of pH value and current density on the efficiency of the leachate treatment were investigated. Meanwhile, it was well understood that using this approach for the treatment of the studied leachate could successfully lower the COD value and color of the leachate wastewater by 81% and 72%, respectively. To the knowledge of the authors, to date, no real leachate samples have been treated by electrocoagulation methods elsewhere. Reference (2) has extensively covered the advantages and drawbacks of various contemporary approaches in landfill leachate treatments. Compared to current treatment processes available today, electrocoagulation can benefit from equipment simplicity; potable, clear, colorless and odorless treated product (6); much larger and stable flocs containing less bound water showing sufficient acid resistance compared to chemical flocs which enables them to be filtered by means of membranes; production of effluents with less total dissolved solids (TDS) content compared to chemical treatments which results in lower water recovery cost in case of water reuse (8); the capability of removing the smallest colloidal particles due to the facilitated coagulation by means of applied electric field (5 ); the absence of chemicals and as a result no secondary pollution which is common in membrane cleaning processes and many other treatment systems. Reference (6) investigated the use of electrocoagulation to treat landfill leachate using surface response methodology. They studied the effects of current density, pH, time and fluid conductivity and the interaction between them to get an optimal turbidity removal. Reference (7) used aluminium plates to electrocoagulate a leachate which had showed low biodegradability and high concentration of macromolecules and then made a quantitative comparison with classical coagulation-flocculation with aluminium ions and also electrolysis alone. This article investigates the application of electrocoagulation in the treatment of a real sample of landfill leachate. The experiments in this study were all carried out in a batch mode in order to evaluate the effects of different operational variables including leachate pH and current density and their effects on the COD and color removal of the leachate wastewater.