PILOT SCALE APPLICATION OF AIR DEPLETION AND LEACHATE RECIRCULATION ON A LANDFILL SITED AR SOUTHEASTERN ARGENTINA

REYES S.; FERNÁNDEZ S.; MARTINEZ A.M.; MORATTO R.; DARQUI M.

Cerdeña. Italia

Simposio; Twelfth International Waste Management and Landfill Symposium; 2009

PILOT SCALE APPLICATION OF AIR DEPLETION AND LEACHATE RECIRCULATION ON A LANDFILL SITED AT SOUTHEASTERN ARGENTINA REYES SERGIO (*), FERNÁNDEZ SANDRA(*), MARTINEZ ANA(*), MORATTO ROCIO(*), DARQUI MARCOS(**). (*) National University of the South, Avda. Alem 1253, Bahía Blanca Argentina. (**) Reyes & Asociados Ltd. Consulting Engineers, Undiano 91, Bahía Blanca Argentina. Key words : Anaerobic, aerobic, organic fraction, degradation, pilot scale cells The evaluation of the degradation rate of organic fraction present in a seventeen year old landfill whose waste mass is affected by lack of appropriate moisture content (Reyes et al. 2007) is key to establish a cost effective full scale degradation system that can shorten the contaminant life span of the facility. A pilot scale study on two cells placed within landfill premises starts construction. On one of the cells air depletion and leachate recirculation will be set up. The other one will only be provided with leachate recirculation. In this way results of aerobic and anaerobic degradation will be compared between them. They will subsequently be used to compare with (landfill full scale) already established natural degradation rates (Reyes et al., 2005, 2007). Also previously obtained aerobic laboratory degradation rates (respiration index) will be compared to field cells´ ones. These latter affected by seasonal climate changes (particularly rainfall, infiltration, wind and temperatures). Rainfall and related infiltration rates have been studied at full scale at the landfill cover by means of lisimeters that have been set up at the site (Reyes et al. 2007). Those results will be compared to recirculated leachate volumes to establish the effect of dryness within the waste mass biological degradation behaviour. Degradation rates will be quantified by comparison of TOC at the initial date of disposal of the waste mass (into cells). Additionally volatile solids content and methane and CO2 measurements at cover exit points during cells´ processes will be registered. The quality of leachate out of both cells will be compared to establish beneficial effects of aerobic degradation versus anaerobic, mainly monitoring ammonium nitrogen and organic pollutants (Ritzkowski M. et al., 2007). The waste mass will be selected to contain at least 70 % content of organic matter by weight (regular percentage of the mass arriving daily is approximately 50 %) to insure readily available quantities of it to be degraded. Chemical waste characterization on samples excavated from the landfill body have been presented previously (Reyes et al. 2005). The issue of the leachate reinjection rate will be closely monitored to maintain the minimum head possible within the cells as per other authors findings on full scale applications (Cossu et al., 2007).