If the 20th century could be characterized by the rapid increase in the production and consumption of materials that helped improving the standards of living, then the 21st certainly has many elements to qualify as the century of recycling. Since the duration of life of a number of wastes is very small (roughly 40% have duration of life smaller than one month), there is a vast waste stream that reaches each year to the final recipients creating a serious environmental problem. The presently most common practice of handling such waste streams is to incinerate them with energy recovery or to use them for land-filling
