Modified flow parameters for leachate generation

Practical waste and flow parameter values were determined to predict accurate leachate breakthrough times and flow rates for landfill leachate. The experimental design, measurement and analytical procedures of a 2(2) factorial experiment with a total of eight cells are developed to validate channeled flow and characterize flow patterns, measure key waste and flow parameters, and determine the effects of infiltration rate and waste density on the flow parameters and leachate discharge. The measured waste and flow parameter values consist of a practical field capacity of 0.12, a pore size distribution index lambda of 0.67, an ultimate moisture content of 1.5 times the practical field capacity, and apparent hydraulic conductivities of less than or equal to 7.3 10(-3) cm/s. These values differ from the HELP water balance model default values. The leachate generation results from the eight pilot waste cells are compared with the HELP predictions. The leachate breakthrough times and discharge volumes compare closely with the measured values if the modified parameters are used in the HELP model. Further research is suggested to construct an appropriate model to predict the channeled and matrix flows. In the mean time, the results in this article provide more accurate waste and flow parameter values for leachate discharge predictions.