الملخص الإنجليزي
Municipal solid waste management helps in ensuring the protection of environment as well as public health. The success of waste management requires accurate data on generation and composition of waste which is pivotal for the decisions regarding the appropriate waste management system. At present there is no data available on solid waste composition and characteristics, collected systematically in Oman. Hence, this preliminary study was conducted in Al-Multaqaa landfill, the only engineered landfill functioning in Oman. Therefore, the main objective of this study is to determine the generation rate, composition and characteristics of municipal solid waste with the intention of providing baseline data for development of municipal solid waste management system.
The samples were collected from the landfill in two different seasons, once in every fortnight and three sampling in each season, i.e., in the months of January and February during winter and in months of May and June, during summer, to represent respective seasons. The sample was collected from four different randomly selected locations of the waste piles, offloaded by the heavy trucks from transfer stations. Following earlier studies, approximately 20kg of so-collected sample was subjected to reduction of the sample size to around 5kg, using quartering technique. Then the reduced sample was sorted out into various components. Subsequently, the weight and volume of each component were measured and recorded.
The daily generation rate is arrived from daily data recorded by the concerned municipality authorities in the landfill. Accordingly, the daily generation of municipal solid waste works out to 0.97 kg /day/person by weight, 3.113 X 10,m®/day/person by volume and with a density of 311.73 kg/m". Regarding the percentage composition of MSW, food waste (mixed) is the predominant constituent, which accounts for 33.62% by weight and 16.69% by volume in winter and 22.74% by weight and 7.84% by volume in summer. Decrease in food waste composition of about 10% is observed in summer compared to winter season, both by weight and volume. Next to food waste, paper waste has the largest proportion both in weight and volume. Plastic waste is the third largest component in the collected sample. Though the weight of the plastic waste is less, its volume is comparatively high.
Proximate analysis, pH and nitrogen content were also analyzed in organic fraction of municipal solid waste. The Organic waste has high moisture content (65%). Calorific value of municipal solid waste is 13,733 kj/kg in winter and 13,142 kj/kg in summer. There is no much difference in the calorific value of MSW between winter and summer. The Global warming potential is calculated using the standard equation developed by Intergovernmental Panel on Climate Change. According to this study, GHG emission from SWDS is 51.97Gg of CO2 equivalent or 2.47 Gg of CH4 equivalents in 1 year.
The study results reveal that the municipal solid waste has the largest proportion of biodegradable and recyclable waste; most of the wastes contain high calorific value. If waste management such as composting, recycling and energy recovery are exercised in the Sultanate, there will be a possibility of reduction in MSW currently getting disposed to the landfill, which in turn, save the landfill area and reduce the amount of green house gas emission from the landfill.
