| Popis: |
An innovative prototype machine was invented for hydrogel bead production, used for preparing novel hydrogel beads, based on biomaterials, fabricated from chitosan (CS), poly(vinyl alcohol) (PVA) and their blend for heavy metal removal from aqueous solution. The adsorption capacity of copper (II) ion onto the beads as adsorbents with their varying compositions and pH from aqueous solution was investigated. The properties of beads were determined using FTIR, SEM-EDX analysis and elemental mapping analysis, and water absorption measurement. The results showed that the CS, PVA and their blend were successfully crosslinked with glutaraldehyde solution. The swelling ratio, equilibrium water content and adsorption capacity depended on their compositions and pH. The spherical appearance of PVA hydrogel bead (PHB) exhibited the equilibrium swelling ratio higher than PVA/CS hydrogel bead (PCHB) and CS hydrogel bead (CHB), respectively. However, the adsorption capacity of copper (II) ion onto CHB was higher than PCHB and PHB, respectively. This behavior is due to their reactive sites being increased, resulting in the increase of interaction between copper (II) ion and CS molecules. Besides, the contact time directly affected the adsorption capacity in aqueous solution. Additionally, it was found that the pseudo-second-order exhibited the best fit for the kinetic studies, indicating the copper being limited by chemisorption process and the mechanism diffusion was controlled by intraparticle diffusion process. All the studied results indicated that hydrogel beads were an efficient and reusable adsorbent for the removal of copper (II) ion from aqueous solutions. |
