Synthesis and evaluation of activated carbon/nanoclay/ thiolated graphene oxide nanocomposite for lead(II) removal from aqueous solution

Water Sci Technol. 2019 Feb;79(3):466-479. doi: 10.2166/wst.2019.071.

Abstract

Novel porous nanocomposite (AC/NC/TGO) was successfully synthesized through the composition of activated carbon, nanoclay and graphene oxide as a Pb(II) adsorbent for the treatment of contaminated aqueous environment. The physicochemical properties and morphology of AC/NC/TGO were examined by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption techniques. Results showed Pb(II) adsorption on the AC/NC/TGO was rapid in the first 20 min and reached equilibrium in 40 min. Kinetic studies showed significant fit to the pseudo second order kinetic model (R2 ≥ 0.9965) giving an equilibrium rate constant (K2) of 0.0017 g mg-1 min-1 for Pb(II) loaded. The experimental adsorption data were better fitted with the Langmuir isotherm model than with the Freundlich isotherm model. Prepared nanocomposite exhibited high values of Brunauer-Emmett-Teller (BET) surface area of 1,296 m2 g-1 and total pore volume of 1.01 cm3 g-1. Maximum adsorption capacity (Qmax = 208 mg g-1) and a relatively high adsorption rate was achieved at pH 5.0 using an adsorbent dose of 0.5 g L-1 and an initial lead concentration of 50 mg L-1. High adsorption capacity, reusability, fast kinetics and simple synthesis method indicate that prepared nanocomposite can be suggested as a high-performance adsorbent for Pb(II) removal from polluted water.

MeSH terms

  • Adsorption
  • Graphite / chemistry
  • Kinetics
  • Lead / analysis*
  • Nanocomposites / chemistry
  • Oxides
  • Spectroscopy, Fourier Transform Infrared
  • Water Pollutants, Chemical / analysis*
  • Water Purification / methods*

Substances

  • Oxides
  • Water Pollutants, Chemical
  • Lead
  • Graphite