Synthesis and employment of magnesium ferrite – chitosan nanocomposite for fluoride removal from aqueous solution with the aid of response surface optimization

Abstract

Background and objectives: Excess fluoride ions in drinking water cause several diseases so the  defluoridation  of  drinking  water  with  excess  fluoride  is  necessary  for  human  health. Hence this work describes fluoride removal from water using MgFe₂O₄ – chitosan nanocomposite.

Material and methods: In this work a nitrate salt of Mg and Fe were used to synthesis MgFe₂O₄ through a combustion route.  Then MgFe₂O_{4 -} chitosan nanocomposite was synthesized using epichlorohydrin as a linker. Characterization of the sorbent was performed with FESEM, TEM, VSM, EDX and XRD techniques. Effective parameters on the adsorption process such as pH, contact time, adsorbent dosage and fluoride concentration was optimized by response surface methodology (RSM) using Box – Behnken design (BBD). Isotherm study was studied at the fluoride concentration range of 10 – 100 mg/L.

Results: The optimum value of pH, contact time, adsorbent dosage and fluoride concentration were 2.8, 4.5 min, 19.0 mg and 28.87 mg/L, respectively. At the optimum condition maximum removal efficiency was 98.1%. Results showed that adsorption process followed Langmuir model with capacity of 181.1 mg/g.

Conclusion: The result of the present work showed that the nanohybrid has good potential as a cheap magnetic sorbent for environmental remediation purpose as can be used for effective removal of fluoride from water solution.