Related Experiment Video
Updated: Jun 25, 2026
08:51
Preparation of Poly(pentafluorophenyl acrylate) Functionalized SiO2 Beads for Protein Purification
Published on: November 19, 2018
Development of multifunctional chitosan beads for fluoride removal
Natrayasamy Viswanathan1, C Sairam Sundaram, S Meenakshi
1Department of Chemistry, Gandhigram Rural University, Gandhigram, Tamilnadu, India.
Journal of Hazardous Materials
|February 10, 2009
Summary
Chemically modified chitosan beads (PCCB) significantly enhance fluoride removal, achieving a defluoridation capacity of 1800 mg/kg. This modified material shows promise for treating fluoride-contaminated water sources.
Area of Science:
- Environmental Chemistry
- Materials Science
- Water Treatment
Background:
- Chitosan beads (CB) exhibit limited defluoridation capacity (DC).
- Fluoride contamination in water poses significant health risks.
- Effective and economical water purification methods are crucial.
Purpose of the Study:
- To chemically modify chitosan beads to improve their fluoride removal efficiency.
- To investigate the defluoridation mechanism and kinetics of modified chitosan beads.
- To assess the practical application of modified chitosan beads for fluoride removal from real water samples.
Main Methods:
- Chitosan beads were chemically modified via protonation and carboxylation to introduce NH(3)(+) and COOH groups.
- Defluoridation capacity was measured and compared between raw and modified beads.
- Sorption behavior was studied concerning pH and the presence of competing anions.
- Sorption isotherms (Freundlich, Langmuir) and kinetic models (pseudo-second-order, intraparticle diffusion) were applied.
- Material characterization was performed using FTIR, SEM, and EDAX analysis.
- The efficacy of the modified beads was tested on field water samples.
Main Results:
- Protonated cum carboxylated chitosan beads (PCCB) demonstrated a maximum DC of 1800 mg F(-)/kg, a substantial increase from raw CB (52 mg F(-)/kg).
- The sorption process was pH-independent and minimally affected by common anions.
- Freundlich and Langmuir isotherms accurately described the fluoride sorption mechanism.
- Sorption kinetics followed pseudo-second-order and intraparticle diffusion models.
- FTIR and SEM with EDAX confirmed the successful modification of chitosan beads.
Conclusions:
- Chemical modification significantly enhances the defluoridation capacity of chitosan beads.
- PCCB is an effective adsorbent for fluoride removal from aqueous solutions.
- The modified chitosan beads show potential for practical application in defluoridation of contaminated water sources, including field samples.
Related Concept Videos
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
04:01Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide: