Adsorptive removal of fluoride from aqueous media using Citrus limonum (lemon) leaf

A novel, the most inexpensive, easily available and eco-friendly analyte (fluoride) adsorbent of treated Citrus limonum (lemon) leaf has been developed and evaluated its feasibility for fluoride ion removal from aqueous environment. The adsorption of fluoride ion was affected by pH, adsorbent dose, contact time and initial fluoride concentrations. Batch experiments were performed to study the influence of various experimental variables such as pH of aqueous solution (2-8), adsorbent dose (1-10 g/50 mL fluoride solution), contact time (5-145 min), initial fluoride concentration (2-15 mg/L) and the presence of few competing anions on the adsorption of fluoride on C. limonum (lemon) leaf adsorbent. The optimal value of pH 2 was observed where the adsorbent showed the maximum defluoridation capacity of 70% of 2 mg/L fluoride ion. The experimental data revealed that both the Langmuir and Freundlich isotherm models fitted with the fluoride sorption process but very well followed Freundlich isotherm model. The reproducibility of the method was validated by removing and analyzing various samples by our method under the optimized conditions. The proposed method was compared with literature reported methods and found to be more effective. The present study demonstrated that treated powdered C. limonum leaf could effectively remediate fluoride contaminated water.