Recycling Technologies

Recycling technologies can be defined as the whole of procedures designed to set up physical-chemical actions, at an industrial scale, that perform the recovery of materials and end-use products that result from the collection of household or industrial wastes. The materials to be recovered and recycled, obviously, influence both processing technologies and plant layouts. In this section an in-depth analysis of the problems arising when suitable recycling technologies must be designed, implemented, and set up is presented with particular reference to paper, glass, metals, plastics, and textiles (not organics or Construction and Demolition (C&D) waste). Recycling technologies must be approached from a processing perspective, that is, by defining a sequence of steps and actions where the waste flow stream feed, and the different products resulting from the different sequential processing steps, are handled in order to produce one or more outputs of materials to reuse. Obviously, processing strategies and equipment must be selected with both low environmental impact and positive economic perspectives in mind. Dealing withwaste often means dealing with complex products, that is, products constituted of one or more materials of interest but also of polluting material. The economic value, per unit of weight, of the materials to recover is usually low: recycling technologies thus must assure high production, while minimizing plant investments and management costs. From this perspective, a full characterization of the input waste streams and complete control of the different phases of the recycling process are a key issue when recycling technologies are selected and applied. In this section, for each of the different materials, methodologies, procedures, and logics are presented to preliminarily identify and quantitatively assess recycling technologies according to the characteristics of the materials to be recovered.