UtilizaÃÃo de fibras de piaÃava (Attalea funifera) na preparaÃÃo de carvÃes ativados. / Utilization of piassava fibers (Attalea funifera) for activated carbons preparation.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The piassava fibers, piassava broom production waste, were used as a precursor to prepare activated carbons. The activated carbons were prepared by chemical activation with zinc chloride, phosphoric acid and iron chloride and by physical activation with carbon dioxide and water steam. The resulting activated carbons were characterized by N2 adsorption/desorption for calculate the BET surface area, elementary analysis (CHN), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR) and scanning eletronic microscopy (SEM). The adsorption capacity of the materials were tested for water contaminants models: methylene blue, reactive red, phenol, Cr+6, Cu+2 and Zn+2 ions. The activated carbons showed high yield, the materials obtained by chemical activation exhibited higher yield than those obtained by physical activation. The CA ZnCl2 showed the largest surface area (1190 m2 g-1) whereas the CA H3PO4 showed the highest pore volume (0,543 cm3 g-1). The CHN analysis revealed that the contents of carbon were increased whereas the contents of hydrogen and oxygen were decreased after pyrolysis and activation process. The TGA in N2 showed that the activated carbons are stables up to 500ÂC, except CA FeCl3, which is stable up to 300ÂC. The SEM images showed that the carbons have similar morphologies, but they are different of the precursor. The infrared spectra showed that the materials were pirolysed. The materials are good adsorbents for the tested contaminants models. The CA ZnCl2 was more efficient in the adsorption of methylene blue and Cu+2 ion. The CA H2O was better adsorbent for reactive red and phenol, while the CA CO2 was better for Cr+6 and Zn+2 ions.

ASSUNTO(S)

1. carvÃo ativado. 2. fibras de piaÃava. 3. adsorÃÃo. 4. contaminantes orgÃnicos. 5. metais. 1. activated carbon. 2. piassava fibers. 3. adsorption. 4. organic contaminants. 5. metals. analise de tracos e quimica ambiental analise de tracos e quimica ambiental 1. activated carbon. 2. piassava fibers. 3. adsorption. 4. organic contaminants. 5. metals. 1. carvÃo ativado. 2. fibras de piaÃava. 3. adsorÃÃo. 4. contaminantes orgÃnicos. 5. metais.

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