An attempt to perform water balance in a Brazilian municipal solid waste landfill

Palavras chave:
Water balance; MSW landfill; Leachate;

This paper presents an attempt to model the water balance in the metropolitan center landfill (MCL) inSalvador, Brazil. Aspects such as the municipal solid waste (MSW) initial water content, mass loss due todecomposition, MSW liquid expelling due to compression and those related to weather conditions, suchas the amount of rainfall and evaporation are considered. Superficial flow and infiltration were modeledconsidering the waste and the hydraulic characteristics (permeability and soil–water retention curves) ofthe cover layer and simplified uni-dimensional empirical models. In order to validate the modeling procedure,data from one cell at the landfill were used. Monthly waste entry, volume of collected leachateand leachate level inside the cell were monitored. Water balance equations and the compressibility ofthe MSW were used to calculate the amount of leachate stored in the cell and the corresponding leachatelevel. Measured and calculated values of the leachate level inside the cell were similar and the model wasable to capture the main trends of the water balance behavior during the cell operational period.