There is a mechanical solution to separating out the waste and categorize them; these machines are called Trommels. They are heavy duty screening machines widely used in the waste processing industry and MSW plants to separate the different types of waste.
A trommel screen consists of a cylindrical drum which has many different size holes on its surface and works in a circular motion. As the drum rotates, the screen allows a particular size waste to be separated out forming a pile eg manure while the waste that is bigger than the size of the hole is retained at the back of the cylinder.
However, the machine requires some manpower for smooth operation, it is easy to use and operation safe. It is even possible to operate a trommel for both dry and wet waste. They are highly effective machines which play an important role in our Zero Waste Mission as waste recycling and waste reuse is only possible once the waste is correctly separated.