Assessment of the composition and characteristics of legacy waste of Kiteezi landfill as a potential for landfill mining.

Abstract

The growing challenges of sustainable municipal solid waste (MSW) management in rapidly urbanizing cities, particularly in Sub-Saharan Africa, demand innovative solutions such as landfill mining (LFM). This study assessed the composition and characteristics of legacy waste at Kiteezi Landfill in Kampala, Uganda, to evaluate its potential for LFM and resource recovery. A total of 40 excavated waste samples were collected from 20 systematically selected pits at different depths and strata. Waste was analyzed for fractional composition, physical properties and chemical characteristics. Results indicated that soil-like material was the dominant fraction (55.3%), followed by plastics (17.4%) and textiles (9.4%), with fine particles (<10 mm) dominating the particle size categories and accounting for 41% of the total. The waste exhibited a mean bulk density of 316 kg/m³, pH of 8.9, and high organic content (organic matter 73.9%, organic carbon 43%). Proximate analysis revealed a mean moisture content of 55.85%, ash content of 26.07%, Volatile matter of 6.63%, Fixed Carbon of 11.44% and calorific value averaging 14.34 MJ/kg. Elemental analysis showed Elemental concentrations largely falling below UNBS and FAO limits, except for lead and selenium, which exceeded FAO recommended thresholds, indicating environmental risks if reused without treatment. Statistical analysis confirmed significant variations in waste composition and properties across depths, indicating the influence of depth and stratification on waste properties. The findings underscore the presence of recoverable materials and energy-rich fractions, supporting the feasibility of LFM as a sustainable waste management strategy and a potential for a circular economy. In Uganda and other developing nations, this study offers vital baseline data for planning environmental remediation, resource recovery, and urban land reclamation. The results can serve as a baseline for developing suitable technologies for mining, reclamation or decommissioning projects at landfills or dumpsites and highlight opportunities for using fine waste particles as composite and building materials. Overall, the study confirms that Kiteezi’s legacy waste holds significant resource recovery potential and it is recommended that future LFM initiatives incorporate appropriate pre-treatment technologies and environmental safeguards to enable safe utilization and support sustainable land reclamation.