Chemodynamic features of nickel(II) and its complexes: Implications for bioavailability in freshwaters

A robust description of the bioavailability of Ni(II) in freshwaters is fundamental for the setting of environmental quality standards. Current approaches assume that bioavailability is governed by the equilibrium concentration of the free metal ion in the bulk aqueous medium. Such strategies generally have limited predictive value: a suite of empirical fitting parameters is required to deal with variations in water chemistry. Herein we compile data on Ni(II) speciation under typical freshwater conditions and compute the lability of Ni(II) complexes with typical molecular and nanoparticulate components of dissolved organic carbon. In combination with an analysis of the kinetic setting of Ni(II) biouptake by freshwater organisms, we assess the potential contribution from dissociation of Ni(II) complexes to the diffusive supply flux of free Ni2+. The strategy takes into account the absolute and relative magnitudes of the Michaelis-Menten bioaffinity and bioconversion parameters for a range of freshwater organisms, together with dynamic chemical speciation descriptors under environmentally relevant conditions. The results show that the dissociation kinetics of Ni(II) complexes play a crucial role in buffering the free metal ion concentration at the biointerface. Our results highlight the need to couple the timescales of chemical reactivity with those of biouptake to properly identify the bioavailable fraction of Ni(II) in freshwaters..

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:241

Enthalten in:

Ecotoxicology and Environmental Safety - 241(2022), Seite 113840-

Sprache:

Englisch

Beteiligte Personen:

Raewyn M. Town [VerfasserIn]
Herman P. van Leeuwen [VerfasserIn]

Links:

doi.org [kostenfrei]
doaj.org [kostenfrei]
www.sciencedirect.com [kostenfrei]
Journal toc [kostenfrei]

Themen:

Bioavailability
Biouptake
Dynamic chemical speciation
Environmental pollution
Environmental sciences
Michaelis-Menten
Nickel

doi:

10.1016/j.ecoenv.2022.113840

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

DOAJ036748560