Keywords: landfill leachates, leachate quality, leachate treatment, biological treatment, coagulation, flocculation, ozonation, municipal landfills, Greece
Characterisation and treatment of leachates from the municipal sanitary landfill of Thessaloniki, Greece
The optimum treatment technologies of leachates produced from a municipal landfill were studied in this work. Leachates composition ranged from high-strength acidic down to low-strength stabilised leachates, affecting the applicable treatment process. Efficient treatment of fresh leachates was achieved by biological methods, such as the SBR, or the moving bed processes, resulting in increased removal of organic and nitrogen content. However, biological methods were not effective for the treatment of stabilised leachates, containing non-biodegradable compound; physical-chemical methods were proved to be more efficient. The combination of coagulation/flocculation followed by ozonation was an efficient technique, with low effluent COD values, <180 mg/L.