The road to nowhere: equilibrium partition coefficients for nanoparticles

Author(s)
Antonia Praetorius, Nathalie Tufenkji, Kai-Uwe Gross, Scheringer Martin, Frank von der Kammer, Menachem Elimelech
Abstract

Adequate fate descriptors are crucial input parameters in models used to predict the behaviour and transport of a contaminant in the environment and determine predicted environmental concentrations for risk assessment. When new fate models are being developed for emerging contaminants, such as engineered nanoparticles (ENPs), special care has to be applied in adjusting conventional approaches and fate descriptors to a new set of substances. The aim of this paper is to clarify misconceptions about the applicability of equilibrium partition coefficients, such as the octanol–water partition coefficient (Kow) or the soil–water distribution coefficient (Kd), whose application in the context of ENP fate assessment is frequently suggested despite lacking scientific justification. ENPs are present in the environment as thermodynamically unstable suspensions and their behaviour must be represented by kinetically controlled attachment and deposition processes as has been established by colloid science. Here, we illustrate the underlying theories of equilibrium partitioning and kinetically controlled attachment and discuss why the use of any coefficient based on equilibrium partitioning is inadequate for ENPs and can lead to significant errors in ENP fate predictions and risk assessment.

Organisation(s)
External organisation(s)
Eidgenössische Technische Hochschule Zürich, McGill University, Helmholtz-Zentrum für Umweltforschung, Yale University
Journal
Environmental Science: Nano
Volume
1
Pages
317-323
No. of pages
7
ISSN
2051-8153
DOI
https://doi.org/10.1039/C4EN00043A
Publication date
07-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
104023 Environmental chemistry, 104002 Analytical chemistry, 105904 Environmental research, 210006 Nanotechnology
ASJC Scopus subject areas
General Environmental Science, Materials Science (miscellaneous)
Portal url
https://ucrisportal.univie.ac.at/en/publications/72ca58fe-571c-4c4b-9c31-d704cd7ae007