Influence of polymer structural parameters and experimental conditions on metal anion sorption by chitosan

✍ Scribed by Guibal, Eric; Dambies, Laurent; Milot, Céline; Roussy, Jean

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 152 KB
• Volume: 48
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199908)48:8<671::aid-pi198>3.0.co;2-v

✦ Synopsis

Chitosan is effective at removing molybdate from acidic solutions, especially when it is stabilized by crosslinking treatment. The in¯uence of structural and physicochemical properties of chitosan and the glutaraldehyde crosslinking step on molybdate has been studied. This study shows that the maximum sorption capacity mainly depends on the crystallinity and degree of deacetylation. Hydration and accessibility to internal sites are controlled by these parameters, which may explain the intraparticle diffusion control on mass transfer. Chitosan gel beads can be used instead of ¯aked particles to decrease sorbent crystallinity. These sorbents were used in column systems, and the breakthrough curves obtained under several experimental conditions (¯ow velocity and column depth) were modelled using numerical analysis. Molybdate-impregnated chitosan beads (MICB) can be used for As(V) removal: sorption isotherms show high sorption levels even at low arsenic concentrations, and at pH 2±3, arsenic removal is optimal and molybdenum release is minimal. The desorption and regeneration of the sorbent was effective using phosphoric acid solutions.