Activated carbon obtained from sapelli wood sawdust by microwave heating for o-cresol adsorption

作者：Thue Pascal S; dos Reis Glaydson S; Lima Eder C; Sieliechi Joseph M; Dotto G L; Wamba Alfred G N; Dias Silvio L P; Pavan Flavio A

来源：Research on Chemical Intermediates, 2017, 43(2): 1063-1087.

DOI：10.1007/s11164-016-2683-8

• Activated carbon
• Microwave-assisted pyrolysis
• o-Cresol
• Kinetic models

Activated carbon (AC) was prepared from sapelli wood sawdust using a microwave heating process. The biomass was mixed with inorganic components (lime + ZnCl2 and FeCl3) to form a homogeneous paste. The AC samples are denoted as AC-1A (100 g sapelli wood sawdust + 20 g lime + 80 g ZnCl2), AC-2A (150 g sapelli wood sawdust + 20 g lime + 80 g ZnCl2), AC-1B (100 g sapelli wood sawdust + 20 g lime + 40 g ZnCl2 + 40 g FeCl3), and AC-2B (150 g sapelli wood sawdust + 20 g lime + 40 g ZnCl2 + 40 g FeCl3). The samples were placed in a microwave oven and pyrolyzed under nitrogen flow. To increase their porosity, the pyrolyzed samples were subjected to a leaching process (with 6 mol L-1 HCl) under reflux to eliminate inorganic components. Several analytical techniques such as Fourier-transfo rm infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and N-2 isotherm and vapor adsorption analyses were performed to characterize the AC materials. The samples presented high Brunauer-Emmett-Teller (BET) surface areas, up to 941.08 m(2) g(-1) for AC-1A. The AC materials were tested for their o-cresol removal ability by determining the best fits to equilibrium and kinetic data using the Sips isotherm and fractional-order model, respectively. The maximum adsorption capacity of the AC samples as obtained from the Sips model was correlated with the surface area. The proposed adsorption mechanism suggests that hydrogen bonding, donor-acceptor complexation, and pi-pi ulated industrial effluents, showing very good efficiency. Almost complete regeneration of the AC adsorbents was achieved using 10 % EtOH + 5 mol L-1 NaOH as eluent. These results demonstrate that sapelli wood sawdust is a promising precursor for preparation of AC to remove o-cresol from aqueous solution.

• 出版日期2017-2