title: Spatially explicit fate modelling of nanomaterials in natural waters.
abstract: Site specific exposure assessments for engineered nanoparticles (ENPs) require spatially explicit fate models, which however are not yet available. Here we present an ENP fate model (NanoDUFLOW) that links ENP specific process descriptions to a spatially explicit hydrological model. The link enables the realistic modelling of feedbacks between local flow conditions and ENP fate processes, such as homo- and heteroaggregation, resuspension and sedimentation. Spatially explicit simulations using five size classes of ENPs and five size classes of natural solids showed how ENP sediment contamination 'hot spots' and ENP speciation can be predicted as a function of place and time. For the catchment modelled, neglect of spatial heterogeneity caused relatively small differences in ENP retention. However, simplification of the number of size classes to one average class, resulted in up to 3.3 times lower values of retention compared to scenarios that used detailed size distributions. Local concentrations in sediment were underestimated up to 20 fold upon simplification of spatial heterogeneity or particle size distribution. We conclude that spatial heterogeneity should not be neglected when assessing the risks of ENPs.
authors.affiliation: Wageningen University, Aquatic Ecology and Water Quality Management Group, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Joris T K
authors.initials: JT
authors.lastname: Quik
authors.affiliation: Wageningen University, Aquatic Ecology and Water Quality Management Group, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Jeroen J M
authors.initials: JJ
authors.lastname: de Klein
authors.affiliation: Wageningen University, Aquatic Ecology and Water Quality Management Group, P.O. Box 47, 6700 AA Wageningen, The Netherlands; IMARES - Institute for Marine Resources & Ecosystem Studies, Wageningen UR, P.O. Box 68, 1970 AB IJmuiden, The Netherlands. Electronic address: Bart.Koelmans@wur.nl.
authors.forename: Albert A
authors.initials: AA
authors.lastname: Koelmans
mesh_terms: D000465:Algorithms; D002563:Cerium / Q000737:chemistry; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry; D057446:Hydrodynamics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008962:Models, Theoretical; D010316:Particle Size; D045483:Rivers / Q000737:chemistry*; D012834:Silver / Q000737:chemistry
chemical_list: D002563:Cerium; D012834:Silver; C030583:ceric oxide
keywords: Fate models; Hydrology; Nanomaterials; Nanoparticles; Rivers; Water quality models