Biogenic iron oxides for phosphate removal

Raimonda Buliauskaitė, Philipp Wilfert, Prashanth Suresh Kumar, Weren W.J.M. de Vet, Geert Jan Witkamp, Leon Korving*, Mark C.M. van Loosdrecht

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Biogenic iron oxides (BioFeO) formed by Leptothrix sp. and Gallionella sp. were compared with chemically formed iron oxides (ChFeO) for their suitability to remove and recover phosphate from solutions. The ChFeO used for comparison included a commercial iron-based adsorbent (GEH) and chemically oxidized iron precipitates from groundwater. Despite contrary observations in earlier studies, the batch experiments showed that BioFeO do not have superior phosphate adsorption capacities compared to ChFeO. However, it seems multiple mechanisms are involved in phosphate removal by BioFeO which make their overall phosphate removal capacity higher than that of ChFeO. The overall phosphate removal capacity of Leptothrix sp. deposits was 26.3 mg P/g d.s., which could be attributed to multiple mechanisms. This included adsorption on the solid phase (6.4 mg P/g d.s.) as well as removal via precipitation and/or adsorption onto suspended complexes released from the BioFeO of Leptothrix sp. (19.6 mg P/g d.s.). Only a very small part of phosphorus (0.3 mg P/g d.s.) was retained in the Leptothrix sp. sheats during bacterial growth. Deposits of Gallionella sp. had an overall phosphate removal capacity of 39.6 mg P/g d.s. Significant amounts of phosphate were apparently incorporated into the Gallionella sp. stalks during their growth (31.0 mg P/g d.s.) and only one-fifth of the total phosphate removal can be related to adsorption (8.6 mg P/g d.s.). Their overall ability to immobilize large quantities of phosphate from solutions indicates that BioFeO could play an important role in environmental and engineered systems for removal of contaminants.

Original languageEnglish (US)
Pages (from-to)260-266
Number of pages7
JournalEnvironmental Technology (United Kingdom)
Volume41
Issue number2
DOIs
StatePublished - Jan 15 2020

Bibliographical note

Publisher Copyright:
© 2018, © 2018 Wetsus. Published by Informa UK Limited, trading as Taylor & Francis Group.

Keywords

  • Gallionella
  • Leptothrix
  • Phosphate
  • adsorption
  • biogenic iron oxides

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology
  • Waste Management and Disposal

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