Seasonal variations in municipal landfill leachate quality

Purpose - The aim of this work is to compare quality of leachates from regional municipal landfill in different seasons (dry, snowy/rainy) during a three-year monitoring period due to the fact that quality of landfill leachate can rapidly change under different conditions. Design/methodology/approach - Raw leachates were sampled prior to biological treatment at different periods of the year (November 2007, March 2008, May 2008, March 2009, and January 2010) to detect the changes in their composition due to different physico-chemical conditions at the site (temperature, moisture, etc.). Leachates were physico-chemically characterized and the toxicity of chosen leachates was assessed by a battery of biotests. Findings - Most of the investigated raw leachates exceed Slovenian effluent limits. Samples from March 2008 and March 2009 generally showed higher concentration of measured parameters and also higher toxicity. It has been confirmed that the physico-chemical parameters of leachates usually decrease during rainy/snowy seasons, in addition to the change in toxicity. Originality/value - This paper demonstrates the need to evaluate the physico-chemical parameters and toxicity of landfill leachate during different seasons of the year to achieve an appropriate assessment of its environmental impact.