Preparation and characterization of charcoal from feathers and its application in trimethoprim adsorption

Abstract

Feathers were utilized to prepare charcoal which could be used for the adsorption of the antibiotic trimethoprim (TMP). The physicochemical properties of the feather-derived charcoal were determined. The feather-derived charcoal had a surface area of 805.4 m²/g and a well-developed microporous structure. The contents of acidic and basic functional groups on feather-derived charcoal were 1.36 and 1.76 mmol/g, respectively, and pH_pzc = 7.52. We studied the influences of adsorbent dose, initial TMP concentration, agitation time, temperature, pH, and ionic strength on the adsorption. The desorption properties of TMP-sorbed feather-derived charcoal were also tested. The adsorption kinetics accorded with the pseudo-second-order kinetic equation, and the overall rate of adsorption was mainly controlled by intra-particle diffusion. The adsorption isotherms for the TMP-feather-derived charcoal system are explained better by the Freundlich isotherm at lower temperature (293 K) while the Langmuir isotherm gave a better fit at higher temperature (313 K). It is considered that a combination of hydrophobic interactions and ion exchange as well as electrostatic interaction was the adsorption mechanisms.

Keywords:

• Feather-derived charcoal
• Trimethoprim
• Adsorption
• Mechanism
• Desorption

Acknowledgements

This work was supported by the Natural Science Foundation for Distinguished Young Scholars of Shandong province (JQ201216), National Water Special Project (2012ZX07203-004) and Independent Innovation Foundation of Shandong University (2012JC029). The authors thank Dr. Pamela Holt for editing the manuscript prior to submission.