Preparation and Properties of a Novel Eco-friendly Carboxymethylcellulose /K- Carrageenan /Graphene oxide Gel Beads for the Removal of Heavy Metals from Water

Abstract

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 30^oC. 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