Síntese e caracterização de hidrocarvão magnético de casca de arroz por carbonização hidrotérmica

Abstract

The growing generation of agro-industrial waste in Brazil is driving the search for sustainable reuse alternatives, especially for materials such as rice husk, an abundant by-product with low added value. The objective of this work was to synthesize and characterize a magnetic hydrochar from rice husk, with a view producing a functional material with potential for environmental applications. The methodology employed involved hydrothermal carbonization of the biomass at 180 °C for six hours, followed by magnetization of the hydrochar using iron salts (ferric nitrate and ferrous sulfate) in an alkaline medium. The material was characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC). The results showed that the magnetized hydrochar had a heterogeneous and porous surface, a composition rich in carbon, oxygen, and iron, a partially amorphous structure with iron oxide phases, and the presence of oxygenated functional groups. These attributes indicate that the material produced has favorable characteristics for application in adsorption and environmental remediation processes. This study demonstrates the feasibility of using rice husk as a raw material in production of sustainable magnetic adsorbents, contributing to the development of technologies in line with circular economy principles.