Sorption kinetic and isotherm study
Batch adsorption isotherm studies were carried out using Type
C hair in all three oil types. Experiments were performed in
triplicate with samples withdrawn at intervals ranging from 5 to
80 min. The experimental data obtained were analysed using
Lagergren pseudo-first-order and second-order kinetic models
[29] and the Langmuir [30] and Freundlich [31] adsorption
isotherm models. The experiments were conducted with varying
weights of the adsorbents to determine the adsorption capacities.
The kinetics and adsorption isotherm were also investigated.
Reusability test
There are different methods in which the adsorbent can be
recovered and reused, e.g. compression, centrifugation, solvent
extraction [32]. The solvent extraction method was employed in
this research. In evaluating the reusability of human hair for oil
sorption, the used human hair adsorbent was first washed with hot
and cold water. All remaining oil was then extracted using
n-hexane. The recovered adsorbent was then dried in a desiccator
and reused for the batch adsorption experiments in four
continuous cycles after each desorption test.