Understanding fluoride adsorption from groundwater by alumina modified with alum using PHREEQC surface complexation
Francis Adu-Boahene1, Patrick Boakye2,3, Frank Ofori Agyemang4
1Department of Civil Engineering (Regional Water and Environmental Sanitation Centre, Kumasi), Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana.
Scientific Reports
|July 29, 2023
Summary
This study transforms aluminum waste into alumina nanoparticles for effective fluoride removal from water. The developed adsorbent shows high efficiency, offering a cost-effective solution for preventing fluorosis.
Area of Science:
- Materials Science
- Environmental Chemistry
- Nanotechnology
Background:
- Fluoride is essential for dental and skeletal health but toxic at high concentrations, causing fluorosis.
- Effective and affordable fluoride removal methods are crucial for public health.
- Valorizing waste materials into functional adsorbents is an sustainable approach.
Purpose of the Study:
- To develop cost-effective alumina nanoparticles from aluminum foil for fluoride removal.
- To investigate the adsorption mechanism and optimize conditions for fluoride removal.
- To validate the adsorbent's performance using real groundwater samples and geochemical modeling.
Main Methods:
- Alumina nanoparticles synthesized from aluminum foil and modified with alum.
- Characterization using FTIR, point of zero charge, and XRD.
- Optimization of adsorption parameters (pH, concentration, contact time, dosage) using simulated and real groundwater.
- Geochemical modeling with PHREEQC and parameter estimation for mechanism elucidation.
- Isotherm and kinetic studies (Langmuir, Freundlich, pseudo-second-order).
Main Results:
- Modified alumina nanoparticles demonstrated high fluoride removal efficiency.
- Adsorption followed Langmuir and Freundlich models, indicating chemisorption on a monolayer surface.
- Pseudo-second-order kinetics best described the adsorption process.
- Ion exchange or surface attraction was identified as the primary sorption mechanism.
- PHREEQC modeling accurately simulated fluoride sorption.
Conclusions:
- Valorized aluminum waste provides a sustainable source for effective fluoride removal adsorbents.
- The developed alumina-based material is a promising solution for treating fluoride-contaminated water.
- This approach contributes to waste valorization and improved public health by mitigating fluorosis risks.
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