Technical possibilities for recycling plastics from agribusiness

Abstract

Plastic waste generated by the Ecuadorian agro-industrial sector represents one of the main environmental impacts, particularly in floricultural and banana production, as a result of its use as a greenhouse cover and as a protective element for the fruit cluster, respectively. The situation become more complicated because of the level of degradation caused by environmental exposure and the degree of contamination due to the use of agrochemicals that plastics present once their useful life has expired. The current research was divided into two stages: characterization of plastic waste and conditioning prior to reprocessing. The results revealed the plastic waste of the floricultural and banana sector, whose predominant material corresponds to LDPE and HDPE, respectively, presents a level of contamination that allows them to be considered as “non-hazardous” waste, which allows them to be recycled, but their processes must be properly controlled and carried out by qualified people. The level of degradation in the exposed banana bags showed losses of mechanical properties of tensile less than 50%, which means that the material is not degraded and it is feasible to recycle it directly. Additionally, the FTIR-ATR spectra on both sides of the film in the samples did not register representative bands of oxidation. On the other hand, in the greenhouse waste, the losses of mechanical properties of tensile strength above 50% as well as the noticeable formation of carbonyl groups in the structure of the material showed the degradation of the plastic. Therefore, the feasibility of recycling will depend on the incorporation of virgin material. The conditioning of the waste for subsequent recycling revealed the need of a washing process consisting of four stages: initial cleaning, pre-wash, washing, and air-drying.