Mature landfill leachate treatment in a biological filter using scoria as media

Abstract

Treatment of leachate and municipal wastewater has extended worldwide using already existing wastewater treatment plants. A biological aerated filter was used to treat leachate from Mexico City's largest landfill together with synthetic wastewater. After achieving stable operation of the filter under organic surface area loading rates of 8.1, 5.3, and 3.1 gCOD/m2·d, landfill leachate was added to the wastewater in volume proportions of 1, 2, and 3%. With leachate, COD removal decreases with increasing leachate concentration. Without leachate, complete nitrification was achieved with the two lower organic surface area loading rates and 93% NH4-N removal was achieved with the highest load. NH4-N removal was 71 and 39% with 2 and 3% leachate, respectively. The oxygen uptake rates decrease with increasing leachate concentration. With 3% leachate, O2 uptake rates for endogenous respiration are higher than for substrate respiration.