Analysis of the environmental benefits of introducing municipal organic waste recovery in Hanoi city, Vietnam

摘要

Hanoi, the capital of Vietnam, is home to approximately 7 million people. In 2011, the city generated about 2,372,500 tons of municipal solid waste (MSW) (accounting for 11% of national generation) and the collection rate reached 85%, of which 84% was sent directly to landfills (without landfill gas capture systems). This conventional practice has caused not only adverse environmental impacts but also increased greenhouse gas (GHG) emissions and loss of recyclable resources. Since most of the waste generated in the city is organic waste (it accounts for 71% of municipal solid waste), there is high potential for organic waste recovery of MSW in Hanoi. This paper analyzes the potential for environmental benefits of introducing composting of municipal organic waste by proposing five alternative scenarios that range from current situation to composting of both commercial and household organic waste. In order to evaluate the environmental performance of the scenarios, we used three indicators: organic fertilizer production, landfill life extension, and GHG emission reduction. The results show that composting could produce a huge amount of organic fertilizer (i.e. from 6,424to 218,650 tons/year) depending on the scenarios. Diversion of organic waste to composting could reduce the amount of waste disposed in landfills resulting in extending landfill life significantly. Therefore, landfill life could be extended from 0.5 to 8.7 years compared to the current situation. Current MSW management practices contributed the highest amount of GHG emission accounting for 1,322,928 tonsCO2-eq/year, whereas the proposed scenarios decrease emissions in accordance with increasing the amount of organic waste used for composting. The estimated emission reduction from the proposed scenarios ranges from 15% to 98% compared to the current situation. The results suggest that composting could bring significant environmental benefits and is a key solution toward sustainable solid waste management for Hanoi city. In addition, composting highlights the potential of climate protection in the waste management sector.