An innovative approach to bioremediation of mercury contaminated soils from industrial mining operations

Damien McCarthy, Grant C. Edwards, Mae S. Gustin, Andrew Care, Matthieu B. Miller, Anwar Sunna

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Soils contaminated with mercury (Hg) have proved expensive and logistically difficult to remediate. Research continues into finding suitable environmentally-friendly and efficient ways of achieving this end. Bioremediation is an option, which employs the strategies microorganisms have evolved to deal with Hg. One microbial strategy involves uptake and intracellular volatilisation of mercuric ions, which passively diffuse from the cell and back into the atmosphere. In this work, Pseudomonas veronii cells grown to stationary phase were immobilised in a xanthan gum-based biopolymer via encapsulation. The P. veronii-biopolymer mix was then coated onto natural zeolite granules. Zeolite immobilised cells remained viable for at least 16 weeks stored under ambient room temperature. Furthermore, the immobilised cells were shown to retain both viability and Hg volatilisation functionality after transportation from Australia to the USA, where they were applied to Hg contaminated soil. Maximum flux rates exceeded 10 μg Hg m2 h−1 from mine tailings (≈7 mg kg−1 Hg with 50% v/v water). This was 4 orders of magnitude above background flux levels. It is envisioned that emitted gaseous elemental mercury (GEM) can be readily captured, and transformed back into metallic Hg, which can then be stored appropriately or recycled. This breaks the Hg cycle, as GEM is no longer translocated back to the atmospheric compartment. The immobilising excipients used in this research overcome many logistical issues with delivery of suitable microbial loads to locations of mercury contamination and presents a facile and inexpensive method of augmenting contaminated sites with selected microbial consortia for bioremediation.

LanguageEnglish
Pages694-699
Number of pages6
JournalChemosphere
Volume184
DOIs
Publication statusPublished - Oct 2017

Fingerprint

Environmental Biodegradation
Bioremediation
Mercury
bioremediation
Soil
Biopolymers
Cells
volatilization
Vaporization
Soils
Zeolites
Immobilized Cells
zeolite
Volatilization
Xanthan gum
Fluxes
encapsulation
Microbial Consortia
Tailings
Encapsulation

Keywords

  • volatilisation
  • mercury bioremediation
  • xanthan gum
  • zeolite
  • biopolymer

Cite this

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title = "An innovative approach to bioremediation of mercury contaminated soils from industrial mining operations",
abstract = "Soils contaminated with mercury (Hg) have proved expensive and logistically difficult to remediate. Research continues into finding suitable environmentally-friendly and efficient ways of achieving this end. Bioremediation is an option, which employs the strategies microorganisms have evolved to deal with Hg. One microbial strategy involves uptake and intracellular volatilisation of mercuric ions, which passively diffuse from the cell and back into the atmosphere. In this work, Pseudomonas veronii cells grown to stationary phase were immobilised in a xanthan gum-based biopolymer via encapsulation. The P. veronii-biopolymer mix was then coated onto natural zeolite granules. Zeolite immobilised cells remained viable for at least 16 weeks stored under ambient room temperature. Furthermore, the immobilised cells were shown to retain both viability and Hg volatilisation functionality after transportation from Australia to the USA, where they were applied to Hg contaminated soil. Maximum flux rates exceeded 10 μg Hg m2 h−1 from mine tailings (≈7 mg kg−1 Hg with 50{\%} v/v water). This was 4 orders of magnitude above background flux levels. It is envisioned that emitted gaseous elemental mercury (GEM) can be readily captured, and transformed back into metallic Hg, which can then be stored appropriately or recycled. This breaks the Hg cycle, as GEM is no longer translocated back to the atmospheric compartment. The immobilising excipients used in this research overcome many logistical issues with delivery of suitable microbial loads to locations of mercury contamination and presents a facile and inexpensive method of augmenting contaminated sites with selected microbial consortia for bioremediation.",
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An innovative approach to bioremediation of mercury contaminated soils from industrial mining operations. / McCarthy, Damien; Edwards, Grant C.; Gustin, Mae S.; Care, Andrew; Miller, Matthieu B.; Sunna, Anwar.

In: Chemosphere, Vol. 184, 10.2017, p. 694-699.

Research output: Contribution to journalArticleResearchpeer-review

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AU - Gustin, Mae S.

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AU - Sunna, Anwar

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