Around 60% of waste generated by city dwellers is organic, as of today, in most cases this potential energy source heads to a landfill where it decomposes, generating also valuable amounts of methane that could be used for the energy grid.
Systems that can decompose this fraction of waste, while harvesting the energy embedded in it can have a direct effect in both the energetic state of the city, reducing how much pollution it generates, as well as keeping landfills for exclusive materials and slowing the rate in which they fill.
Industrial composting is a keystone in this strategy, as organic waste generated by cities is very diverse in the composition of materials. Education is also key in the process of classification.
There are emerging systems that can also treat the organic fraction of urban waste locally and creatively, saving costs of transporting the waste.
Black Soldier Fly Larvae are increasingly studied as a great candidate to reduce some types of organic waste, they feed in the organic matter and depending on the source of the waste, the larva and pupa can be used as feed for poultry or fish directly or there can be a further separation of protein and fat which can be used as a source of Bio-Diesel.
There are many resources online such as the video below that show how this biotechnology is applied successfully in many tropical parts of the world such as Indonesia and even outside tropical regions like in London and the Netherlands.
More research involving this systems and its acceptance of the community and government has to be done before we see these bio-technologies applied successfully. A composting unit for small scale research has been designed for digital fabrication in sheets of Plywood, lined with plastic and adapting a drainage system to retrieve liquids, as well as a shade-cloth strap-on "lid".
These designs can be easily be fabricated by CNC or Laser Cutting machine, transported and assembled on site with minimal tools. Key elements such as the angles and dimensions of the composting units were already tested in other materials and fabrication techniques so performance data generated can be compared with important research previously done in Costa Rica.
If you are interested in building your own, you can request the files with this google form:
https://goo.gl/forms/MqLn1EUjUhVEFna92