Sorting waste and recycling has all different approaches. You can sort manually and you can also leverage technology to help reduce labor and automate.
The core goal when sorting recyclables is to reach 99% clean or better on the final sorted materials for export. This is best accomplished by removing bulky materials first and implementing as many systems and technologies to automate removal of smaller materials without the cost of labor down-stream.
Current transitions in these types of systems include implementation of robotics, optical sorters, magnets, eddy currents etc. to reduce error and increase efficiency.