Quantifying greenhouse gas emissions from municipal solid waste dumpsites in Cameroon

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Waste Management

Background:

• Open dumpsites are recognized as substantial sources of atmospheric greenhouse gas (GHG) emissions.
• Limited data exists on GHG emissions from dumpsites in Central Africa's unique climate and management conditions.
• Municipal solid waste management practices significantly influence environmental pollution and climate change.

Purpose of the Study:

• To quantify methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from two open dumpsites in Cameroon.
• To assess the impact of waste characteristics and environmental conditions on emission rates.
• To provide data for developing effective waste management strategies in the region.

Main Methods:

• Field measurements of CH4, N2O, and CO2 fluxes were conducted at Mussaka-Buea and Mbellewa-Bamenda dumpsites during the wet season.
• Dumpsite surfaces were zoned based on waste activity and age for targeted measurements.
• Static flux chambers were employed to quantify gas emission rates thrice daily.

Main Results:

• Average emissions at Mussaka dumpsite: 96.80 mg CH4 m⁻² min⁻¹, 0.20 mg N2O m⁻² min⁻¹, and 224.78 mg CO2 m⁻² min⁻¹.
• Average emissions at Mbellewa dumpsite: 213.44 mg CH4 m⁻² min⁻¹, 0.15 mg N2O m⁻² min⁻¹, and 1103.82 mg CO2 m⁻² min⁻¹.
• Significant variations in emissions were observed across different waste zones, attributed to waste heterogeneity and decomposition stages.

Conclusions:

• Open dumpsites in Cameroon are significant sources of CH4, N2O, and CO2 emissions.
• Waste management activities like soil covering can mitigate emissions, while disturbance can increase them.
• Recommendations include upgrading dumpsites to sanitary landfills and implementing biogas capture systems to reduce GHG impact.