Solid Waste Management
Management of Municipal Solid Waste (MSW) is one of the major challenges worldwide. Inadequate collection, recycling or treatment and uncontrolled disposal of waste in dumps lead to severe hazards, such as health risks and environmental pollution. This situation is especially serious in low and middle-income countries.
Often more than 50% of the total municipal waste
is organic. Enhancing resource recovery activities at an early stage, as close
to the source as possible, can alleviate significant problems of transport and
disposal. Therefore, Sandec’s research on Solid Waste Management is focusing on
appropriate treatment technologies of the organic fraction of Municipal Solid
Waste.
Research
Themes:
Anaerobic Digestion of Organic Solid Waste
Besides composting or direct animal feeding, anaerobic digestion (biomethanation) of organic solid waste is considered promising treatment option for this particular waste fraction. Anaerobic digestion is a natural biological process that converts biomass into energy (biogas) in the absence of oxygen. Biogas – a mixture of CO2 and methane (CH4) – can be used as a renewable energy source for cooking, lighting or to generate electricity, thereby replacing other fuel sources. Biogas digestate is a nutrient-rich fertiliser that can be applied in gardens or agriculture.
The existing physical plan and socio-economical situation of many cities in low and middle-income countries strongly favours the implementation of decentralised systems. Decentralised composting systems are less technology dependent. Low cost, locally available materials and simple technology can be used.
Conversion of Organic Refuse by Saprophages (CORS)
Saprophages are all organisms feeding of dead or decaying matter. Typical examples are earthworms, millipedes or insect larvae. Conversion of organic refuse by saprophages is an innovative technique to treat organic waste in low and middle-income countries, with degraded organic matter and saprophage organisms themselves as treatment products.