Complexation of silver and dissolved organic matter in soil water extracts. (April 2015)

• Record Type: Journal Article
• Authors: Settimio, Lara; McLaughlin, Mike J.; Kirby, Jason K.; Langdon, Kate A.; Janik, Les; Smith, Scott
• Is Part Of: Environmental pollution. Volume 199(2015)
• Page Start: 174
• Page End: 184
• Publication Date: 2015-04
• Subjects: Silver -- Dissolved organic carbon -- Soil -- Complexation -- Spectroscopy; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2015.01.027
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: An important aspect of the behaviour and fate of silver (Ag) in soils is the interaction with dissolved organic matter (DOM). The complexation and strength of binding of Ag + with DOM in soil water extracts was examined and modelled based on a range of chemical and quality DOM measurements. Silver ion binding measured by addition of the 110m Ag radioisotope in addition to a cation exchange resin technique were used to determine strongly complexed Ag in solutions. Silver was found to be up to 70% strongly complexed. The variability in Ag + binding by DOM across different soils was closely related (R 2 = 0.8) to the mid-infrared spectra of these extracts. The affinity of Ag + for DOM was stronger in solutions containing a greater content of humic and aromatic structures. The ability of Ag + to complex with DOM could result in increased mobilisation of this metal in the soil environment. Highlights: Ag releases to the environment are likely to increase due to its increased usage. Dissolved organic matter (DOM) is critical to the availability of Ag + . Across a range of different soils there was up to 70% complexed Ag in solution. Variation in Ag + binding by DOM across soils was closely related to the MIR spectra. Ag + affinity for DOM was stronger for DOM with greater humic and aromatic content. Abstract : Strongly complexed Ag in soil water extracts was closely related to the mid-infrared spectra of the extracts and the strength of binding to humic and aromatic structures of DOM.