A field investigation of the quantity and quality of leachate from a municipal solid waste landfill in a Mediterranean climate (Thessaloniki, Greece)

Sanitary landfill leachates belonging to different stabilization stages were systematically sampled and 20 of the most commonly examined pollution parameters were determined on a seasonal basis. Selected important relationships between these parameters were defined and statistical evaluation of the results has been performed. The composition of leachates varied widely, depending mainly upon their degree of stabilization and upon their seasonal production, representing the influence of different climatic conditions. All parameters examined showed markedly higher values when leachates were collected 'fresh', while pH tended to increase gradually with time from slightly acidic towards alkaline values in leachate that is older, and therefore more stabilized. Toxic metal concentrations were found to be relatively low in 'fresh' leachate samples and even lower in the aged ones. Finally, suggestions have been proposed for the subsequent treatment of leachates, based upon hydrological and leachate quality data, in order to avoid environmental deterioration problems caused by direct disposal. (C) 2002 Elsevier Science Ltd. All rights reserved.