CHARACTERIZATION OF PLASTIC MATERIALS PRESENT IN MUNICIPAL SOLID WASTE: PRELIMINARY STUDY FOR THEIR MECHANICAL RECYCLING

Abstract

In the EU, 25.8 million tons of plastic wastes are generated each year and more than 30% end up in landfills. In Spain, this percentage rises up to 50%. Mechanical recycling is currently one of the best alternatives to reduce problems associated with poor management of plastic waste. In this paper, an analytical laboratory study of several samples of municipal plastic waste from Granada (Spain) was presented. The samples were supplied by the Waste Treatment Plant (Ecocentral). The study was based on the measurement of the moisture and dirt content of the selected plastic waste. Those parameters were determined by washing and drying the waste and analyzing the washing wastewater; in order to determine/justify the need of a washing step and a post-treatment of the washing water. The results showed that the differences in moisture and dirt content were significant between the different types of polymers, which could influence in the economic profitability of mechanical recycling. Polystyrene (PS) is the material that loosed the most weight while polypropylene (PP) loosed least weight. Moreover, the washing wastewater shows parameters that comply with the discharge regulations of Granada (Spain), except for the case of polyethylene film, whose wastewater would require pre-treatment prior to discharge. Overall, the results were satisfactory, as they show that most of the ordinary plastic waste can be recycled without high cost.