Relationship of Field Capacity with Geotechnical Parameters in an Urban Solid Waste Landfill

Abstract

One of the main environmental problems of landfills of urban solid waste is the release of leachate which can result in soil and water contamination. Leachate represents one of several risk factors for the environment, since it has high concentrations of polluting agents. The possibility of knowledge about the leachate generation is important for the evaluation of the efficiency of a treatment system, as well as the knowledge of the soil and waste field capacity is also essential to implement a control of the total moisture content in the landfill that influences biodegradation and methane production. The objective of this work was to evaluate the use of an efficient method of obtaining the field capacity for the layer of grounded solid waste cover, relating them to several geotechnical parameters. The obtaining of the field capacity of the soil and the residues consisted of driving the sampling cylinder through a backhoe, statically driving the small Shelbys (10.4 to 11.8 cm in diameter by 20 cm in height) to obtain the samples. In the laboratory, the samples had their ends sawn to remove excess waste, where they were then placed in a large bucket with a gravel mat, approximately 15 cm, to facilitate the saturation of the sample by the hydrostatic process of vessels communicants, where, after reaching saturation, they were placed in free drainage conditions in order to reach field capacity. The tests indicated that the average field capacity for the soils was 35%; for new wastes values ??varying from 43 to 56% and for old wastes values ??of volumetric field capacity ranging from 30 to 44%. Thus, it was observed that many empirical models used in dimensioning leachate treatment plants do not take into account a variable that directly influences leachate production.