The flow inside an adsorption column for the treatment of landfill leachate is a poorly understood parameter due to lack of studies on its fluid dynamics. In order to address this matter, axial dispersion modelling was conducted to determine the flow pattern of landfill leachate in a column with palm shell-activated carbon (PSAC) as media. In addition, the treatment profile of leachate via adsorption onto PSAC in terms of chemical oxygen demand (COD) and turbidity removal as well as leachate pH was studied. Lithium chloride (LiCl) was used as a non-reactive tracer. The vessel dispersion number (D/uL) was determined to be between 0.01 and 1, implying small and slow dispersion occurring in a plug flow-like dynamics. The model was applicable for modeling of leachate flow inside a pack bed column. Empty bed contact time (EBCT) was utilized to determine the treatment profile with regards to COD and turbidity removal from leachate. The highest 50% breakthrough of COD removal at 1460 mg/g was obtained at EBCT of 14.7 min. The EBCT has no significant effect on turbidity removal and effluent pH. (c) 2008 Elsevier B.V. All rights reserved.