[Fe-Mn Binary Oxide Impregnated Chitosan Bead (FMCB): An Environmental Friendly Sorbent for Phosphate Removal]

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Phosphate pollution is a significant environmental concern, necessitating efficient removal methods.
• Chitosan-based materials offer potential as adsorbents due to their biocompatibility and functional groups.
• Developing novel composite sorbents can enhance adsorption performance for target pollutants.

Purpose of the Study:

• To fabricate and characterize an environmental-friendly Fe-Mn binary oxide impregnated chitosan bead (FMCB) for phosphate removal.
• To investigate the adsorption behavior, capacity, and kinetics of FMCB for phosphate.
• To evaluate the performance of FMCB in simulated groundwater and its regenerability.

Main Methods:

• Fabrication of FMCB by impregnating Fe-Mn binary oxide into a chitosan matrix.
• Characterization using Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area analysis.
• Systematic investigation of phosphate adsorption including batch experiments, kinetic modeling (pseudo-second order), and isotherm modeling (Langmuir).

Main Results:

• FMCB exhibited a porous, fibrous structure with a high BET surface area (248 m²·g⁻¹) and pore volume (0.37 cm³·g⁻¹).
• The maximum adsorption capacity reached 13.3 mg·g⁻¹ at pH 7.0, significantly higher than pure chitosan.
• Adsorption followed the pseudo-second order kinetic model and Langmuir isotherm, with performance influenced by pH and coexisting ions.

Conclusions:

• FMCB is a highly effective and regenerable sorbent for phosphate removal from aqueous solutions.
• The material's properties, including high surface area and specific adsorption mechanisms, contribute to its excellent performance.
• FMCB shows promise for practical application in treating phosphate-contaminated water sources.