Fluoride removal from water using a magnesia-pullulan composite in a continuous fixed-bed column.

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Fluoride contamination in water poses significant health risks.
• Magnesia-pullulan composite (MgOP) has demonstrated potential for fluoride removal.
• Industrial-scale application requires evaluation of continuous processes.

Purpose of the Study:

• To assess the industrial-scale application of MgOP for fluoride removal using a continuous fixed-bed column.
• To investigate the influence of various operational parameters on fluoride adsorption efficiency.
• To evaluate the stability of magnesium in the composite and the material's regenerability.

Main Methods:

• Utilized a continuous fixed-bed column setup to test MgOP performance.
• Investigated parameters including bed mass, flow rate, fluoride concentration, temperature, pH, and co-existing anions.
• Modeled fluoride adsorption dynamics using Thomas and Yan models and monitored effluent magnesium concentrations.

Main Results:

• Achieved a defluoridation capacity of 16.6 mg/g under optimal conditions (6.0 g bed mass, 16 mL/min flow rate, 10 mg/L initial fluoride concentration).
• The Yan model provided a better prediction of breakthrough curves compared to the Thomas model.
• Magnesium leaching was within safe limits, and calcination effectively regenerated the MgOP material.

Conclusions:

• MgOP is a promising material for industrial-scale fluoride removal from water.
• The Yan model accurately describes the fluoride adsorption dynamics in the fixed-bed column.
• MgOP exhibits good stability and regenerability, making it a viable option for sustainable water treatment.