Activated carbon quality produced by Tectona grandis wastes: activation methods and adsorption capacity

Abstract

Activated carbons (AC) are high porosity and adsorptive carbonaceous materials. These adsorbents can be produced using different organic materials. Precursor material properties may impact their quality. This study aimed to produce activated carbon from Tectona grandis wood wastes, besides determining efficiency in adsorption of different pollutants. Chemical activation, with ZnCl2 (AC_ZnCl2) and CuSO4 (AC_CuSO4), and physical activation, with CO2 (AC_CO2) were performed. Activated carbons were characterized by FTIR, surface functional groups (Boehm) and surface area analysis. Moreover, ACs were tested regarding adsorption capacity of methylene blue (MB), phenol and Cr+6 ions in aqueous medium. Higher total pore volume (0.62 cm³ g-¹), micropore volume (0.31 cm³ g-¹) and surface area (524.50 m² g-¹) were obtained in AC_ZnCl2, which was also the most effective in MB and phenol adsorption. AC_CuSO4 obtained high adsorption capacity for phenol and presented functional groups different from the other AC. AC_CO2 was the second with better adsorption performance for all pollutants.

Keywords: Activation process. Adsorbent. Forest wastes. Raw material.