ABSTRACT
Palm Kernel Shell and Coconut Shell were utilized for the
preparation of activated Carbon (AC) by microwave assisted
NaCl/CaCl2 chemical activation at microwave radiation power of 700W and
radiation time of 20 minutes. The activated carbon Samples were
characterized by, Scanning Electron Microscopy (SEM) coupled with Energy
Dispersive X-,Ray Spectroscopy, X- Ray Diffraction (XRD), moisture
content, ash content and adsorption study.
The moisture content in all the samples fall within the acceptable range of less than 70%, according to Tierney et al.,2006,
which indicates that the adsorption of moisture by the samples is also
less. Among the activated carbon samples, sample E has the least
moisture content of 6.50 % and an ash content of 3.66%, which suggests
that sample E is very viable for adsorption.
The adsorptive properties of the AC samples were quantified using
methylene blue (MB), as a model adsorbate. Results showed that the
adsorption capacities of the AC samples for MB fitted well in the
Langmuir model of adsorption with a maximum adsorption capacity of
333.3mg/g.The adsorption capacity was influenced by theporosity of
activated carbon of which the development of the porosity of activated
carbon was affected by the Microwave power and the presence of
activating agents for impregnation.
In SEM, Sample E gives a clearer pore structure, having more volume
of pores and better pore structures with little agglomeration, making
it more viable for adsorption in comparison with the other prepared
samples.
In XRD characterization, the presence of irregular patterns of
X-Ray diffractograms may be accounted for amorphous state of the
samples. A sharp peak, which corresponds to CaCl2, was observed at 26.5°
and also, sharp peaks corresponding to NaCl, were observed at two theta
31.5° and 45.0° in Sample E.The findings revealed the potential use of a
blend of Palm Kernel and Coconut Shells derived activated carbon for
dyes removal and/or impurities within the size range of 1.5nm from
wastewater, in general and for the removal of MB, in particular.