Gas emissions as influenced by home composting system configuration

Area of Science:

• Environmental Science
• Waste Management
• Atmospheric Chemistry

Background:

• Home composting systems (HC) are vital for municipal solid waste management.
• Limited data exists on the environmental impact, specifically greenhouse gas emissions (GGE), of various HC configurations.

Purpose of the Study:

• To identify home composting configurations that minimize methane (CH4) and nitrous oxide (N2O) emissions.
• To compare the GGE performance of different composting systems.

Main Methods:

• Four types of HC (wood bin, plastic bin, mixed ground pile, unmixed ground pile) were used to compost food and yard waste for 150 days.
• Carbon dioxide (CO2), CH4, and N2O emissions were measured weekly from day 15 using a closed chamber method.
• Compost characteristics, including moisture content, were monitored.

Main Results:

• Methane (CH4) emissions were not detectable between day 15 and 150.
• Nitrous oxide (N2O) generation occurred from day 20 to 120.
• The plastic bin (PB) showed the lowest N2O emissions (56 kg CO2-eq/tonne wet waste) due to continuous aeration from top and bottom slots.

Conclusions:

• The plastic bin (PB) configuration is most effective at reducing N2O emissions among the tested systems.
• Further research is needed on the combined effects of management practices and HC design on gaseous emissions, particularly CH4 from day 0 to 15.