Loading…
Equilibrium, kinetics and thermodynamics study of phenols adsorption onto activated carbon obtained from lignocellulosic material (Eucalyptus Globulus labill seed)
Activated carbon was prepared from lignocellulosic material ( Eucalyptus Globulus labill seed) by chemical activation with ZnCl 2 at two different concentrations (10 and 25 % m/v) named ACS25 and ACS10. The textural characteristics of the activated carbons (ACs) were determined by N 2 adsorption iso...
Saved in:
Published in: | Adsorption : journal of the International Adsorption Society 2016-01, Vol.22 (1), p.33-48 |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Activated carbon was prepared from lignocellulosic material (
Eucalyptus Globulus labill
seed) by chemical activation with ZnCl
2
at two different concentrations (10 and 25 % m/v) named ACS25 and ACS10. The textural characteristics of the activated carbons (ACs) were determined by N
2
adsorption isotherms; these exhibit B.E.T. surface areas of 250 and 300 m
2
g
−1
for ACS25 and ACS10, respectively, with micropore volume contents of 0.140 and 0.125 cm
3
g
−1
in the same order. In addition, the FTIR and Boehm methods were conducted for the chemical characterisation of ACs, where many groups with basic character were found, which favours the adsorption of phenols. The prepared carbonaceous adsorbents were used in the adsorption of wide pollutants monosubstituted phenol derivatives: phenol, 4-nitrophenol and 4-chlorophenol. The effect of temperature on the thermodynamics, kinetic and equilibrium of phenols adsorption on ACs was thoroughly examined. The adsorption kinetics adjusted properly for a pseudo-second-order kinetic model. However, the Elovich model (chemisorption) confirms that phenols adsorption did not occur via the sharing of electrons between the phenolic ring and basal plane of ACs because is not properly adjusted, so the process is given by physisorption. The thermodynamic parameters [i.e. Gibbs free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°)] were also evaluated. The overall adsorption process was exothermic and spontaneous in nature. The values found in the thermodynamic study, confirm that the adsorption process corresponds to a clearly physical process. |
---|---|
ISSN: | 0929-5607 1572-8757 |
DOI: | 10.1007/s10450-015-9724-2 |