Uso de fonte renovável para o desenvolvimento de nanocompósitos argila aniônica/carvão hidrotérmico e sua aplicação como adsorventes multifuncionais

Abstract

This works attempts to develop multifunctional materials – nanocomposites –, involving anionic-clays and hydrochar. It was synthesized using hydrothermal carbonization (HTC) of cellulose in the presence of the clay, aiming to use it as an adsorbent for cationic and anionic chemical substances. HTC is promising in the aspect of adding value to waste (biomass/biomolecules), with biomass being a renewable raw material source and abundant for the sustainable production of carbonaceous materials. Two nanocomposite systems were prepared: i) anionic clay made of Mg, Al, sulfate and hydrochar and ii) anionic clay made of Mg, Al, carbonate and hydrochar. For each system, two temperatures (230 and 250 ºC) and two reaction times (4 and 24h) were used. These materials were characterized for its compositional, thermal, structural, textural and morphological properties. Previous adsorption tests using anionic (Reactive blue 19) and cationic (Methylene blue) dyes were performed with the prepared systems. These results indicated that nanocomposite HDLSO4 (230oC e 4h) presented the most promising results regarding the interaction with the anionic and cationic dyes. Therefore, this sample was chosen for additional adsorption experiments. The kinetic curves showed equilibrium time of 480 min for both dyes. The isotherms showed that the maximum capacity of dye removal was, approximately, 121,4 mg/g of Reactive blue 19 and 24,3 mg/g of methylene blue. Thus, the anionic clay/hydrochar nanocomposite presents multifunctionality through adsorption of positively and negatively charged chemical species. The nanocomposite could be applied as a new adsorbent in environmental remediation.