Removal of Barium from Solution by Natural and Iron(III) Oxide‐Modified Allophane, Beidellite and Zeolite Adsorbents

Andre Baldermann*, Yvonne Fleischhacker, Silke Schmidthaler, Katharina Wester, Manfred Nachtnebel, Stefanie Eichinger

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Efficient capture of barium (Ba) from solution is a serious task in environmental protection and remediation. Herein, the capacity and the mechanism of Ba adsorption by natural and iron(III) oxide (FeO) modified allophane (ALO), beidellite (BEI) and zeolite (ZEO) were investigated by considering the effects of contact time, temperature, pH, Ba 2+ concentration, adsorbent dosage, the presence of competitive ions and adsorption-desorption cycles (regenerability). Physicochemical and mineralogical properties of the adsorbents were characterized by XRD, FTIR, SEM with EDX and N 2 physisorption techniques. The Ba 2+ adsorption fitted to a pseudo-first-order reaction kinetics, where equilibrium conditions were reached within <30 min. BEI, ALO and ZEO with(out) FeO-modification yielded removal efficiencies for Ba 2+ of up to 99.9%, 97% and 22% at optimum pH (pH 7.5-8.0). Adsorption isotherms fitted to the Langmuir model, which revealed the highest adsorption capacities for BEI and FeO-BEI (44.8 mg/g and 38.6 mg/g at 313 K). Preferential ion uptake followed in the order: Ba 2+ > K + > Ca 2+ ≫ Mg 2+ for all adsorbents; however, BEI and FeO-BEI showed the highest selectivity for Ba2+ among all materials tested. Barium removal from solution was governed by physical adsorption besides ion exchange, intercalation, surface complexation and precipitation, depending mainly on the absorbent type and operational conditions. BEI and FeO-BEI showed a high regenerability (>70-80% desorption efficiency after 5 cycles) and could be considered as efficient sorbent materials for wastewater clean-up.

Original languageEnglish
Article number2582
Pages (from-to)1-27
Issue number11
Publication statusPublished - 1 Jun 2020


  • Adsorption
  • Barium
  • Environment
  • Surface modification
  • Wastewater treatment

ASJC Scopus subject areas

  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Cite this