A novel environmentally-friendly adsorbents, carboxymethyl cellulose /k-carrageenan /graphene oxide
(CMC/KC/GO) gel beads (GBs) was prepared via a simple method. The composition and morphology of these
gel beads were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and
scanning electron microscopy. The maximum adsorption capacity of (CMC/KC/GO) GBs for Cu (II) and Co (II)
was 2.85 and 1.87 mmol/g respectively at 30oC. Factors affecting the adsorption capacity of metal ions such as
CMC/KC ratios, GO ratios, pH, initial metal ions concentration, and the temperature were also explored. The
kinetics studies showed that the adsorption process followed the pseudo-second-order kinetics. The analysis of
the isotherm indicated that the Langmuir isotherm is in a good agreement with the sorption process. The
thermodynamic parameters indicate that the adsorption process was endothermic and spontaneous. The
adsorption capacity of the GBs barely declined even after six cycles of regeneration; furthermore, the GBs can
be simply separated from the aqueous solution after adsorption by a simple filtration.
Keywords:Carboxymethyl cellulose; k-carrageenan ;graphene oxide ; gel beads; isotherm