NOVEL REMEDIATION OF PFAS CONTAMINATION

Key Researchers: Brett Turner, Glenn Currell

PROBLEM DESCRIPTION

“Fluorinated substances” is a general, nonspecific name that describes a multitude of organic and inorganic chemicals that contain at least one fluorine (F) atom [1]. A subset of these chemicals are the “Perfluoroalkyl” and “polyfluoroalkyl” substances (PFASs) in which the hydrogen atoms of the carbon (C) backbone have been replaced by F atoms. If all H atoms are replaced by F then they are termed “perfluoroalkyl” substances, otherwise they are termed “polyfluoroalkyl” substances.

PFASs have been widely used in food wrappers, textile stains, non-stick cooking utensils, carpet and furniture protectants, insecticides, electronics, and in fire-fighting foams as they are highly effective against hydrocarbon fuel fires. Over 575 firefighting training facilities exist at Air Force, Navy, and Army installations around the world. In Australia a number of sites including Williamtown RAAF base, NSW; Oakey Aviation Centre, Queensland, and the Country Fire Authority (CFA) training facility, Fiskville, Victoria have been identified as having groundwater and soil contaminated with PFAS. The potential extent of this problem for infrastructure is immense with over 41,000 airports in the world many of which potentially contaminated with PFAS.

Considered almost non-degradable in nature many conventional treatment approaches for PFAS remediation are not effective yet the costs of PFAS remediation technologies are exorbitant. For example at a site near Düsseldorf Airport, Germany, the cost of remediation for a single 42 m3 contaminated area exceeded 10 million Euro. Impact on the airport infrastructure and operation during remediation is also potentially high with existing treatment systems requiring large areas space. This theme will focus on developing novel methods for the remediation of groundwater contaminated with PFAS and in addition the application of phytoremediation to address soil PFAS contamination.

SCIENTIFIC AND ENGINEERING APPROACHES

  • Determine the potential of plant proteins (and plant protein mixtures) for ex situ pump and treat methods and in situ application of a permeable reactive barriers (PRB)
  • Systematic evaluation of the kinetics of PFAS removal from solution by various natural plant based media.
  • Determine the sorption parameters of the five target PFAS chemicals for hemp protein powder and separately, the proteins edestin and albumin extracted from the hemp protein powder.
  • Examine the suitability of various nanoparticles to be coated with active plant components (proteins or amino acids) to develop a supercharged nanoparticle for PFAS remediation.
  • Determine the temperature required for destruction of the spent plant substrate material along with the propensity of dangerous gases to be evolved during thermal breakdown. Using advanced thermal methods of thermogravimetric analysis (TGA) with differential scanning calorimetry (DSC) coupled with gas evolved Fourier Transform Infra-Red spectroscopy (FTIR)
  • Phytoremediation testing using hemp plants for the uptake of PFAS contaminants from soil.

APPLICATIONS

  • PRB decrease impact on airport infrastucture
  • Novel PFAS remediation world-wide
  • Novel PFAS soil remediation option
  • Decrease current costs of remediation application

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