title: Non-labile silver species in biosolids remain stable throughout 50 years of weathering and ageing.
abstract: Increasing commercial use of nanosilver has focussed attention on the fate of silver (Ag) in the wastewater release pathway. This paper reports the speciation and lability of Ag in archived, stockpiled, and contemporary biosolids from the UK, USA and Australia, and indicates that biosolids Ag concentrations have decreased significantly over recent decades. XANES revealed the importance of reduced-sulfur binding environments for Ag speciation in materials ranging from freshly produced sludge to biosolids weathered under ambient environmental conditions for more than 50 years. Isotopic dilution with (110 m)Ag showed that Ag was predominantly non-labile in both fresh and aged biosolids (13.7% mean lability), with E-values ranging from 0.3 to 60 mg/kg and 5 mM CaNO3 extractable Ag from 1.2 to 609 μg/kg (0.002-3.4% of the total Ag). This study indicates that at the time of soil application, biosolids Ag will be predominantly Ag-sulfides and characterised by low isotopic lability.
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia; CRC CARE, PO Box 486, Salisbury, South Australia 5106, Australia. Electronic address: erica.donner@unisa.edu.au.
authors.forename: E
authors.initials: E
authors.lastname: Donner
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
authors.forename: K
authors.initials: K
authors.lastname: Scheckel
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Sekine
authors.affiliation: School of Chemical and Physical Sciences, Flinders University, Adelaide, South Australia 5001, Australia.
authors.forename: R S
authors.initials: RS
authors.lastname: Popelka-Filcoff
authors.affiliation: Neutron Activation Group, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia.
authors.forename: J W
authors.initials: JW
authors.lastname: Bennett
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Brunetti
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia; CRC CARE, PO Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Naidu
authors.affiliation: Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, United Kingdom.
authors.forename: S P
authors.initials: SP
authors.lastname: McGrath
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia; CRC CARE, PO Box 486, Salisbury, South Australia 5106, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Lombi
mesh_terms: D001315:Australia; D012722:Sewage; D012834:Silver / Q000032:analysis / Q000737:chemistry*; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013455:Sulfur / Q000032:analysis / Q000737:chemistry; D013997:Time Factors; D006113:United Kingdom; D014481:United States; D062065:Wastewater / Q000737:chemistry*; D014887:Weather
chemical_list: D012722:Sewage; D012834:Silver; D012987:Soil; D012989:Soil Pollutants; D013455:Sulfur; D062065:Wastewater
keywords: Biosolids; E-values; Isotopic dilution; Silver; Speciation; XANES