Desempenho de sistema de tratamento de lixiviado de aterro sanitário com recircula？？o do efluente

the objective of this study was to evaluate the performance of a landfill leachate treatment system, at pilot scale, formed by three in series ponds (l1, l2, and l3) followed by a rock filter. three operational conditions were studied, assessing the effluent recirculation effect from l3 to l1: 0, 50 and 100% of the flow rate. the system assimilated well the load fluctuations, showing removal efficiencies over 80% for bodf, 70% for codt and 98% for ammonia. in the l2 pond there was partial nitrification with nitrite accumulation. it was observed an outstanding presence of the chlamydomonas gender in photosynthetic ponds l2 and l3. a reduction of the toxicity from the landfill leachate was observed, with reduction of over 95% in the system output. the better removal efficiency for the three studied operational conditions was obtained for 100% of recirculation.