Fixed-bed column adsorption modeling using Zr biocomposites for fluoride removal

Area of Science:

• Environmental Science
• Materials Science
• Water Treatment

Background:

• Fluoride contamination in drinking water poses significant health risks.
• Developing sustainable and cost-effective methods for fluoride removal is crucial.
• Agricultural waste, like fruit peels, represents a potential source for novel biosorbents.

Purpose of the Study:

• To synthesize and evaluate zirconium-impregnated biocomposites from orange and apple peels (BOP-Zr, BAP-Zr) for continuous fluoride adsorption.
• To investigate the adsorption mechanisms and kinetics of fluoride removal using packed bed column experiments.
• To assess the stability and reusability of the developed biosorbents.

Main Methods:

• Continuous adsorption experiments were conducted using BOP-Zr and BAP-Zr in packed bed columns.
• Various empirical models (Bohart-Adamas, Thomas, Yoon-Nelson, BDST, Clark, Yan, Woolborska) were applied to analyze adsorption data.
• Adsorption capacity, kinetics, and mass transfer parameters were determined.

Main Results:

• BOP-Zr and BAP-Zr demonstrated selective and effective fluoride removal from drinking water.
• The Yan model best described the adsorption process, indicating pseudo-second-order kinetics and chemical adsorption.
• Maximum adsorption capacities were 59.3 mg/g for BOP-Zr and 47.5 mg/g for BAP-Zr.
• Mass transfer analysis indicated pore diffusion as the rate-limiting step.
• Biosorbents were stable, with no zirconium leaching into treated water.

Conclusions:

• BOP-Zr and BAP-Zr biocomposites are efficient, stable, and environmentally friendly biosorbents for fluoride removal.
• These materials offer a practical and competitive alternative to conventional water treatment methods.
• Utilizing agricultural waste enhances its value and provides a sustainable solution for water purification.