Comparison of physicochemical properties of activated carbons derived from biomass wastes by H₄P₂O₇ activation: adsorption of trimethoprim

Abstract

This work investigated the activated carbons (ACs) derived from three kinds of biomass waste carbon precursors, i.e. Phragmites australis (PA), mushroom root (MR), and chicken feather (CF) with H₄P₂O₇ activation. The effect of different precursors on porous texture, surface chemistry, and adsorption capacities of the derived ACs were comparatively studied. The pore structure and chemical properties of the ACs were characterized by N₂ desorption/adsorption isotherms, element analysis, FTIR, XPS and Boehm’s titration methods. It was found that the surface area and pore volume of AC-PA (S_BET = 986.8 m²/g, V_tot = 1.07 cm³/g) and AC-MR (S_BET = 950.1 m²/g, V_tot = 1.02 cm³/g) were about 1.7 times higher than those of AC-CF (S_BET = 471.4 m²/g, V_tot = 0.28 cm³/g). AC-PA (2.488 mmol/g) possessed more acidic oxygen functionalities than AC-MR (1.736 mmol/g) and AC-CF (1.858 mmol/g), while AC-CF had most basic functional groups. Batch adsorption studies were performed to compare the adsorptive abilities of different ACs for trimethoprim (TMP). It was found that the adsorption affinities of TMP followed an order of AC-PA (244.9 mg/g) > AC-MR (165.6 mg/g) > AC-CF (124.2 mg/g).

Keywords:

• Biomass wastes
• Activated carbon
• Physicochemical properties
• Trimethoprim adsorption

Acknowledgements

This work was supported by the Independent Innovation Foundation of Shandong University (2012JC029), Natural Science Foundation for Distinguished Young Scholars of Shandong province (JQ201216) and National Water Special Project (2012ZX07203-004).