Síntese e caracterização de hidrogel de poli (álcool vinílico) para liberação de NPK e retenção de água em solo

Abstract

In 2050 the world population will be more than 9 billion people and to meet this growing food demand it will be necessary to increase food production by at least 60%. To solve these problems, fertilizers are increasingly being used on plantations, often indiscriminately, resulting in various environmental impacts. As a possible solution to remedy or reduce environmental impacts arising from the incorrect use of fertilizers and waste of water, new technologies have emerged, among them, one of the most promising is the use of hydrogels in the soil, as some have great absorption and release properties. gradual release of water and potential to bind to various substances, enabling the controlled release of fertilizers. Therefore, this work aims at the synthesis and characterization of poly (vinyl alcohol) (PVA) hydrogels for application in rational use of water and release of NPK fertilizers in soil. The hydrogels were called HPVA and synthesized in different proportions considering the stoichiometry in moles of free OH present in PVA per mole of EDTAD, being 10:1, 20:1 and 100:1. They were characterized by Fourier transform infrared absorption spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetry (TG) and swelling capacity. The most stable HPVA was tested for absorption and release of NPK in soil and had its biodegradation and phytotoxicity characteristics evaluated, demonstrating the capacity for controlled release of water and NPK in soil in a bean seedling plantation and not proving to be phytotoxic, in addition to being biodegradable. Therefore, HPVA demonstrated to be a promising material for rational use of water and release of fertilizers into soil.