Molybdate sorption by cross-linked chitosan beads: Dynamic studies
Recent trends in environmental monitoring have induced increasing development of new wastewater treatment techniques. Membrane processes, electrochemical techniques, or ion-exchange systems are widely used, but biosorption has been recognized in the last 30 years as a promising way to reduce the contamination of surface water issued from industrial effluent. Chitosan, a biopolymer extracted from crustacean shells, exhibits high sorption capacities for metal ion recovery. Sorption efficiency and removal rates are controlled by several diffusion mechanisms. Chitosan gel beads have been prepared and have shown enhanced sorption performance in batch systems. This study shows that, in continuous systems, sorption capacities can reach 700 mg/g, a level close to that obtained in batch studies. The effects of metal concentration, flow velocity, and column size are investigated and demonstrate that, because of diffusion mechanisms, the optimum concentration range is approximately 50 to 100 mg/L. In column systems, the Biot number, though greater than 1, is lower than the Biot number obtained in batch systems, indicating that external mass transfer influences mass transfer at the low superficial velocity investigated in this work.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 323716
- Journal Information:
- Water Environment Research, Vol. 71, Issue 1; Other Information: PBD: Jan-Feb 1999
- Country of Publication:
- United States
- Language:
- English
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