Characterization and adsorption properties of eggshells and eggshell membrane.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Environmental Chemistry

Background:

• Eggshell waste presents a disposal challenge.
• Valorization of eggshell waste into functional materials is an area of interest.
• Understanding the physicochemical properties of eggshell-derived materials is crucial for application development.

Purpose of the Study:

• To chemically and physically characterize eggshell and eggshell membrane particles derived from hen eggshell waste.
• To evaluate the potential of these biomaterials as biosorbents for dye removal.
• To investigate the adsorption behavior of methylene blue onto eggshell-derived materials.

Main Methods:

• Preparation of eggshell and eggshell membrane particles from hen eggshell waste.
• Characterization using Fourier Transform Infrared (FTIR) spectroscopy.
• Analysis of pore structure and surface properties.
• Methylene blue adsorption studies at 25°C using Langmuir and Freundlich models.

Main Results:

• Eggshell and membrane particles exhibited Type II pore structures, indicative of nonporous or macroporous materials.
• FTIR spectra confirmed carbonate minerals in eggshell particles and fibrous proteins (amines, amides) in membrane particles.
• Adsorption isotherms followed the Freundlich model better than the Langmuir model.
• Eggshell biosorbents demonstrated low methylene blue uptake (<1.0 mg/g) due to poor pore properties.

Conclusions:

• Hen eggshell and membrane particles possess distinct chemical compositions and pore structures.
• The limited pore properties of these biomaterials restrict their efficacy as biosorbents for basic dyes like methylene blue.
• Further modification or alternative applications may be necessary to fully utilize these waste-derived materials.