Enhanced adsorption of phenol from aqueous solution by carbonized trace ZIF-8-decorated activated carbon pellets

Abstract

Trace zeolitic imidazolate framework-8 (ZIF-8)-decorated activated carbon (AC) pellets were synthesized by a facile wet impregnation technique. After pyrolysis of the above composite material, the obtained carbon had a large surface area and pore volume, with traces of Zn on its surface. Subsequently, the capacity of the ZIF8/AC samples to adsorb and remove phenol from aqueous media was evaluated in both batch and column experimental setups. The equilibrium adsorption capacity reached 155.24 mg·g−1, which was 2.3 times greater than that of the pure AC (46.24 mg·g−1). In addition, adsorption kinetics were examined by pseudofirst and pseudosecond order models, and adsorption isotherms were fitted into Langmuir and Freundlich equations. The adsorbent could be easily filtered from the solution and washed with methanol and water, while maintaining an efficiency > 90% after 4 cycles. The above results make it a potentially reusable candidate for water purification.