Green house gas emission reduction through recycling of municipal organic waste

Abstract

Over the past decades, scientific studies have shown a significant increase in atmospheric concentrations of carbon dioxide (CO2) and other gases that trap heat in the Earth’s atmosphere. Scientists agree that the Earth is getting warmer fast because of the increases of greenhouse gases and as a result climate is changing. Worldwide concern over the effects of climate change led to the creation of the International Panel on Climate Change (IPCC), a collaboration of scientists from around the world. The research effort was followed by the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol, international agreements to address the danger of global climate change. The Dhaka City Corporation (DNCC and DSCC) is responsible for the management of solid waste for an area covering 360 km2 with a population of 7.66 million (BBS, 2011). It reveals from the literature review that waste generation rate of Dhaka City Corporation (DCC) varies from 0.4 to 0.6 kg/cap/day and the total waste generation is 4635 ton/day (Sinha, 2000). The composition of organic waste varies from 79% to 85%. Most part of the waste of DCC (North and South) is organic, a major source of compost. Literature review also shows that an amount of 0.76 million ton of equivalent CO2 (tCO2e) per year which has global warming potential can be reduced through the proper management of the generated waste of DCC (Sinha et al., 2006). This study shows that DCC (North and South) domestic waste in 2011 comprises of food waste varies from 83% to 84%, paper and textile waste 10% to 11% of the total generated domestic waste. The average of the weighted average domestic waste generation rate is 0.46 kg per capita per day which is 35% more than the level in 2004 (0.34kg/cap/day). Analysis shows that there is a correlation between waste generation rate vs GNI and waste generation rate vs population which indicates waste generation rate increases with the increase of GNI as well as increase of population as the correlation coefficients in both cases are 1(one). Based on the projected population in 2012, the domestic waste production of DCC (North and South) is 3646 MT per day and the estimated total wastes production of DCC (North and South) is around 6024 MT per day. It is also found from this study that most part of the generated wastes is organic. The moisture content of the waste in wet season is 80% and the density is 400 kg/m3. It is also seen from analysis that when 100% of the food waste, paper and textile wastes generated from the domestic source are avoided from landfilled and decomposed or recycled, a reduction of greenhouse gas emission potential of 2.87 million tons of equivalent CO2 per year (tCO2e) in 5 years time (2012-2016) is possible to reduce (4% of the baseline emission as project and other emissions have been deducted from BEy to get the actual emission reduction). These amounts of Certified Emission Reduction (CER) of GHG may open up the window of selling carbon credits. Food waste is contributing to the majority of global warming in DCC (North and South). Analysis shows that use of a net input of organic waste 1,109,176 tons in 2012 at the compost plant will produce 277,294 tons of compost which can be used as soil conditioner and can reduce the load on chemical fertilizer which ultimately helps in reducing GHG emission. Treatment of organic waste at the plant will also create job opportunity for local people especially for the poor women. The analysis shows that when only the organic portion of waste is managed and recycled, landfill area (6m depth) requirement will be dropped from 34 to 6 acres and at the same time DCC will have the job opportunity for 10,938 poor people at the treatment plant and 12,156 poor local people for collection and transportation of wastes.