Adsorption of phosphate on iron oxide doped halloysite nanotubes

Dema A. Almasri, Navid B. Saleh, Muataz Atieh, Gordon McKay, Said Ahzi

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Excess phosphate in water is known to cause eutrophication, and its removal is imperative. Nanoclay minerals are widely used in environmental remediation due to their low-cost, adequate availability, environmental compatibility, and adsorption efficiency. However, the removal of anions with nanoclays is not very effective because of electrostatic repulsion from clay surfaces with a net negative charge. Among clay minerals, halloysite nanotubes (HNTs) possess a negatively charged exterior and a positively charged inner lumen. This provides an increased affinity for anion removal. In this study, HNTs are modified with nano-scale iron oxide (Fe 2 O 3 ) to enhance the adsorption capacity of the nanosorbent. This modification allowed for effective distribution of these oxide surfaces, which are known to sorb phosphate via ligand exchange and by forming inner-sphere complexes. A detailed characterization of the raw and (Fe 2 O 3 ) modified HNTs (Fe-HNT) is conducted. Influences of Fe 2 O 3 loading, adsorbent dosage, contact time, pH, initial phosphate concentration, and coexisting ions on the phosphate adsorption capacity are studied. Results demonstrate that adsorption on Fe-HNT is pH-dependent with fast initial adsorption kinetics. The underlying mechanism is identified as a combination of electrostatic attraction, ligand exchange, and Lewis acid-base interactions. The nanomaterial provides promising results for its application in water/wastewater treatment.

Original languageEnglish
Article number3232
JournalScientific reports
Volume9
Issue number1
DOIs
Publication statusPublished - 1 Dec 2019

    Fingerprint

ASJC Scopus subject areas

  • General

Cite this