Resource recovery potential of Kumasi landfill waste

Abstract

Landfill mining is an innovative way to minimize environmental pollution, secure land and airspace, and recover secondary raw materials from landfills. The study examined the characteristics of landfilled waste at the Kumasi landfill and its potential for resource recovery. Samples were collected based on the deposition age and characterized in the laboratory. Characteristics determined were composition, volatile solids, moisture content, and heavy metal concentrations. The results indicated that the most significant recoverable resources were Decomposed Organic Materials (organic waste mixed with sand and papers) and combustibles (plastics, wood, and textile), constituting 44 % and 36 % by weight, respectively. The composition of the landfill waste was found to be influenced by the components of waste initially disposed at the landfill and its subsequent age of deposition. The metal content concentration was, however, independent of the age of deposition. The results indicate that a landfill mining project at the Kumasi landfill will make available about 89 % of the landfill volume and airspace for reuse. However, the DOMs recovered may not be suitable for application as compost on agricultural soils due to the high zinc concentrations unless applied to zinc-deficient soils. It may, however, be used as construction material in earthworks and as cover materials at landfill sites. The combustible component can be combusted to generate heat for producing hot water for hospitals, hotels, and old age care facilities.