RESUMO
This paper presents a mapping of the waste collection systems in Kampala city, using geographical information system (GIS) ArcGIS mapping software. It discusses the existing models of waste collection to the final disposal destinations. It was found that food and yard wastes constitute 92.7% of the waste generated in Kampala. Recyclables and other special wastes constitute only 7.3% of the total waste, mainly because of the increased level of reuse and recycling activities. The generation rate of solid wastes was on average, 582, 169, 105, and 90 tons/day from poor areas, upscale wealthier areas, business centers, and market areas respectively. This tonnage of waste was collected, transported, and disposed of at the city landfill. The study found that in total, residential areas of poor people generate more waste than other categories stated earlier, mainly because of their large populations. In total, there were 133 unofficial temporary storage sites acknowledged by Kampala Capital City Authority (KCCA) but not formally designated, 59 illegal dump sites, and 35 officially recognized temporary waste storage locations. This paper presents large-scale data that can help with understanding the collection models and their influence on solid waste management in Kampala city, which could be used for similar cities in developing countries.
Assuntos
Sistemas de Informação Geográfica , Modelos Teóricos , Reciclagem , Resíduos Sólidos/análise , Gerenciamento de Resíduos/métodos , Cidades , Eliminação de Resíduos , Fatores Socioeconômicos , UgandaRESUMO
UNLABELLED: In Kampala, Uganda, about 28,000 tons of waste is collected and delivered to a landfill every month. Kampala Capital City Authority (KCCA) records show that this represents approximately 40% of the waste generated in the city. The remaining uncollected waste is normally dumped in unauthorized sites, causing health and environmental problems. However, the organic fraction of domestic waste can provide an opportunity to improve livelihoods and incomes through fertilizer and energy production. This study characterized the municipal waste generated in Kampala and delivered to Kiteezi landfill between July 2011 and June 2012, that is, covering the dry and wet months. On each sampling day, waste was randomly selected from five trucks, sorted and weighed into different physical fractions. Samples of the organic waste from each truck were analyzed for total solids, major nutrients, and energy content. During the wet months, the waste consisted of 88.5% organics, 3.8% soft plastics, 2.8% hard plastics, 2.2% paper, 0.9% glass, 0.7% textiles and leather 0.2% metals, and 1.0% others. During the dry months, the waste consisted of 94.8% organics, 2.4% soft plastics, 1.0% hard plastics, 0.7% papers, 0.3% glass, 0.3% textile and leather, 0.1% metals, and 0.3% others. The organic waste on average had a moisture content of 71.1% and contained 1.89% nitrogen, 0.27% phosphorus, and 1.95% potassium. The waste had an average gross energy content of 17.3 MJ/kg. It was concluded that the organic waste generated can be a suitable source of some plant nutrients that are useful especially in urban agriculture. IMPLICATIONS: The result of the waste characterization in Kampala was found to be significantly different from that obtained for other Sub-Saharan African (SSA) cities, showing that studies assuming average values for the waste fractions are likely to result in erroneous results. Furthermore, no reduction in organic fraction of the waste was noticed when compared with a study done two decades ago in spite of greatly improved economic status of Kampala city, a finding that is not in agreement with several other similar studies done for other SSA cities.