title: Analytical characterisation of nanoscale zero-valent iron: A methodological review.
abstract: Zero-valent iron nanoparticles (nZVI) have been widely tested as they are showing significant promise for environmental remediation. However, many recent studies have demonstrated that their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Both the mobility and reactivity of nZVI mainly depends on properties such as particle size, surface chemistry and bulk composition. In order to ensure efficient remediation, it is crucial to accurately assess and understand the implications of these properties before deploying these materials into contaminated environments. Many analytical techniques are now available to determine these parameters and this paper provides a critical review of their usefulness and limitations for nZVI characterisation. These analytical techniques include microscopy and light scattering techniques for the determination of particle size, size distribution and aggregation state, and X-ray techniques for the characterisation of surface chemistry and bulk composition. Example characterisation data derived from commercial nZVI materials is used to further illustrate method strengths and limitations. Finally, some important challenges with respect to the characterisation of nZVI in groundwater samples are discussed.
authors.affiliation: School of Civil and Environmental Engineering, University of Technology, Sydney, Post Box 129, Broadway, NSW 2007, Australia; CRC CARE, PO Box 486, Salisbury, SA 5106, Australia.
authors.forename: L
authors.initials: L
authors.lastname: Chekli
authors.affiliation: School of Chemical Engineering, The University of Adelaide, Engineering North Building, Adelaide, SA 5005, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Bayatsarmadi
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Sekine
authors.affiliation: CRC CARE, PO Box 486, Salisbury, SA 5106, Australia; Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Sarkar
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: A Maoz
authors.initials: AM
authors.lastname: Shen
authors.affiliation: U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Land Remediation and Pollution Control Division, 5995 Center Hill Avenue, Cincinnati, OH, USA.
authors.forename: K G
authors.initials: KG
authors.lastname: Scheckel
authors.affiliation: Ian Wark Research Institute, University of South Australia, Building IW, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Skinner
authors.affiliation: CRC CARE, PO Box 486, Salisbury, SA 5106, Australia; Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Naidu
authors.affiliation: School of Civil and Environmental Engineering, University of Technology, Sydney, Post Box 129, Broadway, NSW 2007, Australia; CRC CARE, PO Box 486, Salisbury, SA 5106, Australia.
authors.forename: H K
authors.initials: HK
authors.lastname: Shon
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia. Electronic address: Enzo.Lombi@unisa.edu.au.
authors.forename: E
authors.initials: E
authors.lastname: Lombi
authors.affiliation: CRC CARE, PO Box 486, Salisbury, SA 5106, Australia; Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, SA 5095, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Donner
keywords: Bulk composition; Characterization techniques; Groundwater remediation; Particle size; Surface chemistry; Zero-valent iron nanoparticles