Zirconium/lanthanum-modified chitosan/polyvinyl alcohol composite adsorbent for rapid removal of fluoride

Int J Biol Macromol. 2023 Jul 15:243:125155. doi: 10.1016/j.ijbiomac.2023.125155. Epub 2023 Jun 1.

Abstract

A novel and easily separable adsorbent in the shape of a membrane for the rapid removal of fluoride from water was prepared after testing Zr, La and LaZr to modify a chitosan/polyvinyl alcohol composite adsorbent (CS/PVA-Zr, CS/PVA-La, CS/PVA-LA-Zr). The CS/PVA-La-Zr composite adsorbent can remove a large amount of fluoride within 1 min of contact time, and the adsorption equilibrium can be reached within 15 min. The fluoride adsorption behavior of the CS/PVA-La-Zr composite can be described by pseudo-second-order kinetics and Langmuir isotherms models. The morphology and structure of the adsorbents were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adsorption mechanism was studied using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and which showed that ion exchange occurred mainly with hydroxide and fluoride ions. This study showed that an easily operable, low-cost and environmentally friendly CS/PVA-La-Zr has the potential to remove fluoride effectively from drinking water in a short time.

Keywords: Adsorbent; Fluoride; Polysaccharide; Synthetic polymer; Water decontamination.

MeSH terms

  • Adsorption
  • Chitosan* / chemistry
  • Drinking Water*
  • Fluorides / chemistry
  • Hydrogen-Ion Concentration
  • Kinetics
  • Lanthanum / chemistry
  • Polyvinyl Alcohol
  • Spectroscopy, Fourier Transform Infrared
  • Water Pollutants, Chemical* / chemistry
  • Zirconium / chemistry

Substances

  • Fluorides
  • Chitosan
  • Polyvinyl Alcohol
  • Lanthanum
  • Zirconium
  • Drinking Water
  • Water Pollutants, Chemical