Change of Hydraulic Conductivity of Landfill Base Due to Leachate-Soil Interactions

During recent years efforts has initiated in many major cities of Iran the other alternative of waste disposal such as recycling and composting , however landfill will be the major option for solid waste and some liquid waste disposal for many years to come. Storage of any waste material in a landfill poses several potential problems in particular groundwater contamination that may occur due to leachate generation . An essential element in isolating landfill from the surrounding environment is the bottom liner or natural earthen liner in the base of landfill that may be subjected to change due to leachate-soil interactions. In this study two methods, shallow well pumping and Guelph permeameter , were used for measurement of saturated hydraulic conductivity in the natural earthen linear of Idfahan Landfill. Two of permeants (water and landfill leachate) were used in the tests and three replications were performed. The results indicated that interactions between soil particles and the leachate between the soil particles cause to reduce significantly the soil hydraulic conductivity. This may be related to the type and concentrations of electrolytes, nutrient contents, re-precipitation and pore clogging of natural earthen liner in the bade of landfill. The result have significant ramifications with respect to the use of clay soils for containment of wastes since an adverse interaction may result in unexpectedly large release rates of contaminants from disposal facilities into the surrounding environment.

کلیدواژه ها:

Landfill leachate ، waste disposal ، Shallow well pumping method ، Guelph permeameter ، clay liners ، hydraulic conductivity