ABSTRACT
Landfill is the ultimate disposal method chosen by the most developed and developing countries to manage the municipal solid waste generated. Soil is the traditional material for landfill cover. It consists of several layers and requires several tons of soil. The virgin soils are costly and increasingly becoming scarce. This problem can be overcome by the utilization of certain suitable waste materials like contaminated sediments, cement kiln dust, shredded waste, sludge, construction waste etc. as alternative landfill cover. Disposal of sewage sludge is one of the real problems in the operation of a Sewage Treatment Plant (STP). In this study sewage sludge is utilized for cover material. Permeability is an important parameter while selecting the cover for a landfill, Falling head permeability test was carried out as per IS 2720-Part17 (1986) to find the permeability of sewage sludge and found as 4.68 × 10−3 cm/s. For controlling the leachate quantity, coefficient of permeability of 1.0 × 10−4 cm/s and 1.0 × 10−5 cm/s is required for daily cover and interim cover respectively. As sludge has high permeability it is not suitable for direct use as temporary cover material. In this study sewage sludge is modified with different percentages of materials like fly ash, lime, coir pith and bentonite to meet the requirement of permeability for the temporary cover. The results revealed that sewage sludge modified with 30% coir pith and 30% bentonite meets the permeability requirement for temporary cover compared with lime and fly ash.
