Enhanced phosphate scavenging with effective recovery by magnetic porous biochar supported La(OH)3: Kinetics, isotherms, mechanisms and applications for water and real wastewater

Bioresour Technol. 2021 Jan:319:124232. doi: 10.1016/j.biortech.2020.124232. Epub 2020 Oct 7.

Abstract

Herein, La(OH)3 decorated magnetic porous biochar (MPBC) was synthesized via KHCO3 activation and hydrothermal processes. The La-to-MPBC mass ratio of 3:1 described as La3-MPBC possessed a monolayer phosphate adsorption capacity of 116.08 mg/g across a pH range of 3.0-6.0 with fast attainment of adsorption equilibrium in 150 min. Moreover, the phosphate adsorption was substantially stable during the interference of various co-existing ions with over 92% of phosphate removal and 77% of desorption efficiency maintained after four recycles. And La3-MPBC was easily separated by magnet force with negligible La and Fe leakages within the pH range of 3.0-10.0. Furthermore, La3-MPBC was supported to achieve phosphate binding through the synergistic actions of electrostatic attraction, ligand exchange, inner-sphere complexation and weak precipitation. Significantly, La3-MPBC exhibited a high performance for decontaminating low-concentration phosphate to meet regulatory requirements. All these results suggested La3-MPBC to be an ideal candidate for phosphate removal in real applications.

Keywords: Adsorption; Biochar; Lanthanum; Magnetic nanoparticles; Phosphate.

MeSH terms

  • Adsorption
  • Charcoal
  • Kinetics
  • Lanthanum
  • Magnetic Phenomena
  • Phosphates
  • Porosity
  • Wastewater*
  • Water
  • Water Pollutants, Chemical*

Substances

  • Phosphates
  • Waste Water
  • Water Pollutants, Chemical
  • biochar
  • Water
  • Charcoal
  • Lanthanum