Nesse trabalho, a oxidação catalítica do contaminante sulfeto em meio aquoso foi estudada na presença de carvão ativado na forma de briquetes mecanicamente resistentes e versáteis produzidos a partir de resíduos da indústria do vinho, i.e., semente e cachos. Caracterizações por microscopia eletrônica de varredura combinada com espectroscopia de dispersão de raios X (SEM/EDS), área superficial Brunauer-Emmett-Teller (BET), Raman, termogravimetria (TG), difração de raio X (XRD) e titulação potenciométrica indicam materiais com alta área mesoporosa e grande quantidade de grupos superficiais oxigenados. Esses briquetes mostraram alta atividade para a oxidação de sulfetos em meio aquoso, mesmo comparados com um carvão ativado comercial de elevada área superficial. A eficiência na oxidação de sulfeto é discutida em termos de dois efeitos: a elevada concentração de grupos superficiais redox do tipo quinona/hidroquinona formados a partir da decomposição do mosto da uva e a alta macro/mesoporosidade dos materiais que facilita a difusão das diferentes espécies durante a reação.

In this work, the catalytic oxidation of the hazardous and unpleasant aqueous sulfide contaminant was investigated by activated carbon in the form of mechanically resistant and versatile briquettes produced from two different wastes of the wine industry, i.e., lex and stalk. Characterization by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), surface area Brunauer-Emmett-Teller (BET), Raman, thermogravimetry (TG), X-ray diffractometry (XRD) and potentiometric titration showed that the materials have high mesoporous area with a large number of surface oxygen functionalities. These briquettes showed high efficiency for the oxidation of sulfides in aqueous medium, which is discussed in terms of two effects: the relatively high concentrations of quinone/hydroquinone surface redox groups formed from the grape must binder and the macro/mesoporosity, which facilitates the diffusion of the different species during the reaction.

Neste trabalho, as vantagens de carbonos funcionalizados com alta área superficial e a forma especial de briquete foram combinadas para a produção de um novo adsorvente de metais. Análises BET, TG, IR, sítios ácidos e EDS sugerem que a funcionalização com HNO3 ocorre por todo o corpo do briquete. Foram estudadas também as isotermas e as cinéticas de adsorção de Cr3+, Zn2+ e do corante azul de metileno.

In this work, the advantages of special briquette shape and high surface area functionalized carbon were combined to produce a novel adsorbent for metals. BET, TG, IR, acid site and EDS analyses suggest that the functionalization with HNO3 and metal adsorption takes place throughout the briquette body. The adsorption isotherms and kinetics have been studied for Cr3+, Zn2+ and the dye methylene blue.

The results of studies on briquetting activated-carbon-based adsorbent materials, prepared from raw materials from the region of Cuyo, Argentina, are reported in this article. Several steps were carried out to obtain activated-carbon briquettes from Eucalyptus camaldulensis Dehn wood. These steps included carbonization of wood to obtain char; blending of char and a novel binder, i.e., grape must; formation of cylinder-like briquettes by pressure; and activation of the resulting material. The material was activated with steam under different temperatures, activation times, and activating agent flow rates. Impact resistance index, axial compressive strength, tensile strength by diametrical compression, BET area, and pore volume were measured for product characterization. Satisfactory surface areas and mechanical strengths were found in the final products.