Acompanhamento da bioatividade do solo puro e tratado durante o processo de biodegradação das blendas de polietileno/amido termoplástico/quitosana (PEBD/TPS/Q) e amido termoplástico/quitosana (TPS/Q)

Abstract

The need of producing polymeric artifacts increasingly powerful and versatile but which have increasingly lower biodegradation times motivates the scientific community to seek combinations of natural and synthetic polymers in order to meet both aspects. The manufacture of the blend LDPE/TPS Starch / Chitosan aims to go against that objective. The biodegradation occurs mostly in the soil. Trying to understand the dynamics of the biodegradation process in soil, this paper monitored the effects caused by deposition of the blend, analyzing different parameters, such as organic carbon, organic matter and microbial carbon, indicating levels of soil quality.The blends were prepared with different concentrations of chitosan, with values set to 0, 7, 5 and 15% of total mass and buried in pure soil and soil treated with humus. The analysis periods were 10, 40, 70, 100 and 130 days, with samples being exposed to the environment. Infrared analysis were performed using Fourier transform, X-ray diffraction, scanning electron microscopy with spectroscopy dispersive energy before and after biodegradation mass loss, after the biodegradation process of the blends. Organic carbon, organic matter, microbial carbon, pH and moisture in the soil.The results obtained after analysis in blend showed that with the passage of time, the biodegradation process happened, considering that carbon levels dropped considerably and oxygen were increased in accordance with the EDS analysis. The FTIR analysis confirmed this fact by showing that there was an intese oxidative process, especially in the initial 70 days in all samples. The X-RD analysis showed that there was a variationin crystallinity, but always with a decrease of this paramenter. The weight loss was also significant and progressive in all samples. Soil results showed that the same is resilient and can recover its characteristics during the biodegradation process. At the beginning of the experiment, especially in the first 40 ays, all evaluated paramenters declined considerably, but returned to baseline levels and maintained these values by the end of the experiment. Experimental design was made and it showed that none of the dependent variables influenced the biodegradion process.