Removal of fluoride from aqueous solution using high surface area activated carbon derived from fish scale solid...

Area of Science:

• Environmental Science
• Materials Science
• Water Treatment

Background:

• Fluoride contamination in drinking water is a significant global health concern.
• There is a critical need for cost-effective adsorbents for fluoride removal.
• Fish scales represent an underutilized, low-cost precursor material.

Purpose of the Study:

• To synthesize and characterize activated carbon from fish scales for fluoride removal.
• To investigate the adsorption performance and mechanism of the synthesized material.
• To evaluate the practical applicability of the adsorbent in treating real water samples.

Main Methods:

• Activated carbon (AC) synthesized using KOH activation of fish scales, followed by carbonization.
• Characterization of AC using N2 adsorption/desorption, FESEM, XRD, and FTIR.
• Batch adsorption experiments to optimize parameters (dosage, pH, concentration, time, temperature) and study adsorption kinetics and isotherms.

Main Results:

• Synthesized AC (AC2) exhibited a high surface area (913 m²/g) and pore volume (0.88 cm³/g).
• Optimal fluoride removal occurred at pH 6.0, with a maximum adsorption capacity of 13.04 mg/g at 303 K.
• Adsorption followed Freundlich isotherm and pseudo-second-order kinetics, indicating a spontaneous and efficient process (ΔGº < 0, ΔHº = -59 kJ/mol).
• Over 75% fluoride removal was achieved within 5 minutes.
• Treated field water samples showed fluoride levels below WHO permissible limits.

Conclusions:

• Fish scale-derived activated carbon is a highly effective and low-cost adsorbent for fluoride removal.
• The adsorption process is spontaneous, feasible, and rapid.
• This material shows significant potential for remediating fluoride-contaminated drinking water sources.