Prediction of landfill leachate quantity in arid and semiarid climate: a case study of Aradkouh, Tehran

This paper represents the application of a developed water balance model (based on a model which has been prepared in Germany) to estimate the quantity of leachate output in arid and semiarid regions. Field capacity, saturated water conductivity, and waste direct evaporation tests were implemented to characterize the basic hydrologic properties of municipal waste and the effect of climate conditions on leachate production. A test cell in Aradkouh landfill with the area of 32 x 50 m(2)was constructed to calibrate and compare the measured values with the results of the model. Since the cell is located in a semiarid climate, evaporation had a crucial role in decreasing the primary leachate quantity. The field capacity of the waste is obtained approximately 32.5% (V/V), which is more than the results of laboratory tests. Besides, the waste permeability of the cell was calculated (1.02 x 10(-6) m/s) that is less than the results of experiments. In order to determine the effect of waste settlement in leachate production, an initial rate of settlement and ultimate settlement by using hyperbolic function has been obtained 0.104 and 146.5, respectively. Although aerobic reactions were not prevailing in the cell due to thermal conditions and incompatibility with the observed values, anaerobic reaction decreased the discharged leachate by 10.82%.