Life cycle assessment of biodegradable waste treatment systems for sub-Saharan African cities

• AD performed best in terms of energy use and GWP and EP.
• A poorly managed AD with large methane losses can perform poorly in terms of GWP.
• VC and FLC performance improved if effect of fish on lake ecosystem is considered.

Most of the waste collected in sub-Saharan African cities is biodegradable but it is usually dumped in landfills, creating environmental and health challenges for residents. However, there are biodegradable waste treatment methods that could mitigate these challenges. This study analysed anaerobic digestion, composting, vermicomposting and fly larvae waste treatments using life cycle assessment (LCA). The impact categories assessed were energy use, global warming and eutrophication potential. The results showed that anaerobic digestion performed best in all impact categories assessed. However, management of the anaerobic digestion process is critical and methane losses must be kept very small, as otherwise they will cause global warming.