Electrochemically enhanced adsorption of phenol on activated carbon fibers in basic aqueous solution

Yanhe Han; Xie Quan; Shuo Chen; Huimin Zhao; Chunyue Cui; Yazhi Zhao

doi:10.1016/j.jcis.2006.03.007

Electrochemically enhanced adsorption of phenol on activated carbon fibers in basic aqueous solution

J Colloid Interface Sci. 2006 Jul 15;299(2):766-71. doi: 10.1016/j.jcis.2006.03.007. Epub 2006 Apr 5.

Authors

Yanhe Han¹, Xie Quan, Shuo Chen, Huimin Zhao, Chunyue Cui, Yazhi Zhao

Affiliation

¹ School of Environmental and Biological Science & Technology, Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian University of Technology, Dalian 116024, China.

PMID: 16600273
DOI: 10.1016/j.jcis.2006.03.007

Abstract

Electrosorption isotherms and thermodynamics of phenol on activated carbon fibers (ACFs) in basic solution, as well as the factors (bias potential, initial concentration, and electrolyte) affecting adsorption/electrosorption kinetics, were investigated. The kinetics, which followed the Lagergren adsorption rate law, exhibited a variety of responses depending on bias potential, initial concentration, and electrolyte. The electrosorption isotherms were in agreement with the classical models of Langmuir and Freundlich, but the former gave more satisfactory correlation coefficients. With electrosorption at a bias potential of 700 mV from the basic solution, a nearly 10-fold enhancement of maximum adsorption capacity was achievable. The electrosorption free energy (DeltaG(ads)), enthalpy (DeltaH(ads)), and entropy (DeltaS(ads)) of phenol on the ACFs were calculated from adsorption isotherms at different temperatures. The results indicated that electrosorption of phenol in basic solution was spontaneous and exothermic. Furthermore, it was assessed that electrosorption occurred by dipole-dipole interaction with DeltaH(ads) of -20.14 kJ mol(-1) besides suppositional electrostatic interaction.