Aerobic microbial activity and solid waste biodegradation in a landfill located in a semi-arid region of Argentina

Abstract

The sanitary landfill of Bahía Blanca city, Argentina, located in a semiarid region, receives 270 tons/day of municipal solid waste. The objectives of the study were: (1) to determine aerobic microbial activity (MA) and waste biodegradation taking into account the age of the waste, and (2) to evaluate the degree of waste stabilization of the oldest cell. MA was determined by CO 2 release and chemical characterization in four cells of different ages of landfill. Furthermore, enzymatic methods were used to determine the effect on MA of leachate addition. Low annual rainfall, the sandy characteristics of the soil, and the use of landfill techniques where rigorous compaction is not performed, contribute to maintaining microenvironments with a sufficient quantity of O 2 to support aerobic degradation processes. Under these conditions, degrading processes are faster, thus explaining why MA in the landfill cell closed in 1992 is stabilized and behaves as an anthrosol. In areas where MA is limited by lack of water (arid and semiarid zones), refuse degradation is limited to favorable humid periods. For that reason, operations favoring fast and efficient aerobic activity should be implemented. © Springer-Verlag and the University of Milan 2011.