Tech: Composting
One of the key challenges for many developing countries is how to deal with the organic part of the waste. Whereas recyclable materials often are handled due to the direct economic value they hold - organics, however, require some infrastructure to be able to process and release that value.
To process organic waste there are several options, but in the context of developing countries there are two that stands out - anaerobic and aerobic decomposition. By managing these processes well you can not only create a valuable material from the organic waste (compost or soil conditioner) - but you also get key positive environmental impacts:
- Removal of methane gas emissions - organic waste that is simply dumped will be decomposing anaerobically in an uncontrolled way, leading to large methane gas emissions - a greenhouse gas 20 times stronger than carbon dioxide
- Safe management of garbage leachate - unsanitary dumping can lead to contaminated water leaching into the ground contaminating ground water
Aerobic decomposition
Aerobic decomposition is traditionally called "composting" and involves piling the incoming organic waste and ensuring that all of the waste is properly aerated, allowing the aerobic bacteria to operate. During the process the waste will heat up to between 60 and 70 degrees celsius, ensuring that harmful contaminants such as helminth eggs are killed.
Resources
Decentralised composting handbook
Anaerobic decomposition
Controlled anaerobic decomposition is done by passing through a container allowing the anaerobic bacteria to operate while collecting the methane gas (often called "biogas") that is produced and using it for purposes such as cooking or turning it into liquefied form. By capturing the methane gas the process is not harmful for the environment and the methane gas can be used for other purposes. .
