Characterization, Digestibility and Anaerobic Treatment of Leachates from Old and Young Landfills

We have evaluated the utility of applying anaerobic digestion treatment to the leachates from two landfill sites receiving solid urban refuse from populations of similar standards of living. Both tips are located in the same area and have very similar climates, but they differ as regards the length of time they have been operated. The leachates from the older tip have much lower levels of organic load, 40% of which was refractory to the anaerobic digestion treatment applied. The digestibility of leachates was studied by using a semicontinuous suspended sludge system.It was possible to remove up to 65% of the soluble COD of leachates from the young tip by means of an anaerobic filter working at HRTs less than 2 days. This system proved to be highly stable when its operating conditions were subjected to perturbations similar to those likely to be suffered by a full-scale plant.