DNA: What is the 'Garbage World Cup' of 21 countries?

This month the Cricket World Cup has ended in India and a unique World Cup has been organized in Japan. But this World Cup is a little different from the World Cups of other sports. There are many big tournaments all over the world, from Cricket, Football, Hockey to Chess, but the World Cup organized in Japan has a garbage collection competition. SpoGomi World Cup was organized in Japan. The name of this event is made up of the words 'Sport' and 'Gomi'. Which is used for garbage in Japan. Teams from 21 countries participated in this unique tournament.