Desenvolvimento e caracterização de um potencial fertilizante nitrogenado incorporado em zeólita e matriz polimérica

Abstract

Research has been carried out in order to obtain nitrogen fertilizers with the main objective of increasing productivity and reducing the loss of nutrients to the environment due to climatic actions. In this study, urea is applied as a nitrogen source in zeolite nanoparticles and incorporated into a polymeric matrix crosslinked by three different divalent ions: Ca2+, Zn2+ and Mn2+. An experiment was carried out using two manganese (ll) reagents, manganese sulfate and manganese chloride. The product obtained was characterized by instrumental techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and Thermal Analysis (TGA/DTG). Through the FTIR technique, it was possible to observe the chemical interactions formed by the crosslinking process. Interactions vary according to the crosslinking ion and the presence of zeolite. The presence of zeolite resulted in a product with more hydroxyls, as indicated by the characteristic band in the highest energy region of the infrared spectrum. The samples crosslinked with zinc showed interactions different from the others, indicating a more complex crosslinking process and presenting characteristic bands of urea in the region of higher energy of the spectrum. In the TGA technique, different thermal stabilities can be observed. This variation occurs due to the interaction of the crosslinking ion with sodium alginate. It can be observed that when added to zeolite, sample degradation occurs in fewer events and the percentage of final residue is higher. By the kjeldhal method, it can be observed that the nitrogen values of the samples are low and that the highest percentage of nitrogen was observed for the samples crosslinked with the zinc cátion.