Abstract:
Nowadays, numerous approaches have been focused for the development of cheaper,
effective and environment friendly adsorbents as alternatives to replace activated
carbon and other adsorbents. In this study, raw Casuariana equisetifolia seeds and p-
toluene sulfonic acid as well as sodium hydroxide (NaOH) treated seeds with and
without microwave treatment were used as adsorbents for the malachite green (MG)
and neutral red (NR) dye removal. The treated adsorbents were prepared by soaking
the seeds in the p-toluene sulfonic acid and NaOH. The microwave-modified
adsorbents were prepared by treating the seeds in the microwave oven with the
frequency of 2.34 GHz, 800 W and 8 min irradiation time before the seeds were treated
with the p-toluene sulfonic acid and NaOH. The adsorbents were characterized based
on the chemical characteristic, physical characteristics and surface morphological. The
batch adsorption experiments were performed for the removal of MG and NR dyes.
The results reveal that microwave-acid-alkali treated C. equisetifolia seeds have the
lowest ethanol-toluene solubility and hot water solubility that determine the quantity
of extraneous materials compared raw and acid-alkali treated seeds. The lowest value
of extraneous materials led to increase the active surface of adsorbent
