Polypropylene (PP), high density polyethylene (HDPE) and low density polyethylene (LDPE) films were studied according to the way their wastes are collected (segregated from or mixed with other residues) by evaluating the amount of impurities and the washing wastewater. It was found that the films from mixed collection presented at minimum 30% of impurities, while the films from segregated (or curbside) collection presented at maximum 10% of impurities. The amount of impurities and the wastewater turbidity indicated that 20% more material can be obtained from the films of segregated colletion, preferred by recyclers, in addition to having a simpler washing process because it only involves solids removal, unlike mixed collection which is associated with the impregnation of wet wastes. The effluents were also evaluated according to the total amount of solids, sediments and concentration of nine metals. The results showed that both types of collection generated similar wastewaters and their treatment requires two steps at the most: sedimentation and effluent dilution in the water body.
Recycling; plastic films; curbside collection; polypropylene; polyethylene; industrial wastewater treatment
