Adsorption of pyrimethamine from wastewater using activated carbons prepared from Daniellia-oliveri sawdust

ABSTRACT

This study, in the quest for rugged, robust and greener and cleaner technology, investigated efficiency ofDaniellia-oliveri sawdust for the removal of pyrimethamine from aqueous medium. Two adsorbents were prepared by carbonising and activating the sawdust with ZnCl₂ and H₃PO₄.The adsorbents were characterised using various methods. Batch adsorption experiments were conducted to evaluate the equilibrium isotherm, kinetics and thermodynamics of the process, and to determine the effects of various experimental conditions. The pH_pzc were 7.6 (for ZnCl₂ activated carbon) and 6.6 (for H₃PO₄ activated carbon). The adsorption of pyrimethamine onto the adsorbents was pH independent. The best isotherms for describing the processes were Langmuir (R² = 0.987) and Dubinin-Radushkevich (R² = 0.996) while the kinetics were pseudo-second order (R = 0.980) and intraparticle (R = 0.985) respectively. The monolayer adsorptive capacities of the adsorbents were 4.27 mg/g and 4.43 mg/g.The processes were spontaneous, thermodynamic feasible and endothermic. The results reveal that the two adsorbents were good prospects for the removal of pyrimethamine from wastewater.

KEYWORDS:

• Adsorption
• Daniellia-oliveri
• sawdust
• pyrimethamine
• H₃PO₄
• Zncl₂

Acknowledgements

Authors acknowledged the Interdisciplinary Research Laboratory, the University of Ibadan for permission to use their Laboratory.

Disclosure of Interest

The authors declare that they have no conflict of interest.

Additional information

Funding

This research was fully funded by authors.