Integrated treatment of landfill leachates including electrooxidation at pilot plant scale.

This paper reports the integration of advanced and conventional technologies to deal with the treatment of landfill leachates. The raw leachate, with average values of COD=4430 mg/L and N-NH(4)(+)=1225 mg/L, was first treated on site by an activated sludge large-scale process reducing the former parameters to 1750 mg/L (av.) of COD and 750 mg/L (av.) of N-NH(4)(+). Next, 50 L/h of the effluent were pumped to a pilot plant that included Fenton oxidation followed by an electrooxidation unit, provided with boron doped diamond anodes (anode area=1.05 m(2)); almost complete removal of the organic matter and ammonium nitrogen was achieved. Comparison of the results with those obtained in the laboratory (70 cm(2) of anode area) was performed observing a similar performance in the kinetics of COD removal, while differences were found in the ammonium removal rates. The specific energy consumption necessary to electro-oxidize the organic load below the disposal limit (COD<160 mg/L) at pilot plant scale was 35 kWh/m(3).