Mechanical Coagulation Process of Landfill Leachate in Removing COD, Ammonia and Colour Using Poly-Aluminum Chloride (PAC) and Alum

Abstract

Sanitary landfill leachate is considered as heavily polluted industrial wastewater,which has extremely high pollution load that may pollute subsoil and ground water. Special attention must be paid for its perfect collection and efficient treatment before disposal. This study was conducted to treat the partially stabilized leachate using coagulation-flocculation process as a single treatment method. Jar test experiments were employed in order to determine the optimum chemical and physical variables including coagulant dose, pH and speed of rapid and slow mixing. Two coagulants were tested in this work : Polyaluminium chloride (PAC) and aluminium sulfate (alum). Performance of PAC which is not widely used in leachate treatment was the main focus of this study. Efficiency of alum as a conventional coagulant in wastewater treatment was determined to compare with PAC effectiveness. The optimum condition was applied to determine the removal of colour, chemical oxygen demand (COD) and ammonia (NH3) using both coagulants.