TY  - THES
AU  - Gottselig, Nina
TI  - The Role of Natural Nanoparticles and Colloids for Phosphorus Binding in Forested Headwater Catchments
VL  - 330
PB  - RWTH Aachen
VL  - Dr.
CY  - Jülich
M1  - FZJ-2016-03828
SN  - 978-3-95806-160-6
T2  - Schriften des Forschungszentrums Jülich Reihe Energie & Umwelt / Energy & Environment
SP  - VIII, 116 S.
PY  - 2016
N1  - RWTH Aachen, Diss., 2016
AB  - Stream waters reflect the natural load of nutrients and minerals cycled within or released from ecosystems; yet, little is known about natural colloids (1-1000 nm) and especially nanoparticles (NNP, 1-100 nm) as nutrient carriers in the complex biogeochemical system of forested headwater catchments. NNP and colloids are recognized as ubiquitous components in natural aqueous phases and have the potential to encapsulate and bind nutrients, yet are often not included in the analysis of terrestrial nutrient cycling processes. The distribution of elements between the different physicochemical forms in solution is an important precursor to understand the mechanisms of ecosystem nutrition, especially for limiting nutrients like phosphorus (P). The size and composition of NNP and colloids in aqueous phases is therefore relevant for the transport of essential nutrients like P.Asymmetric Flow Field Flow Fractionation (AF4) was coupled online to a UV detector for approximation of organic C, a dynamic light scattering device for recording of the hydrodynamic particle diameter, a quadrupole inductively coupled plasma mass spectrometer with collision cell technology (ICP-MS) for elemental size-resolved detection and to an organic carbon detector (OCD) for high sensitive size-resolved organic carbon detection. Method development of hyphenated AF4 was performed whereas online P detection represented a specific challenge due to the low concentrations in many natural waters. Methodological considerations on the oxidation efficiency of OCD, the capability of ICP-MS to detect organic C and on a setup to be able to determine the bioavailability of NNP and colloid bound P were assessed. Stream waters of forested headwater catchments were sampled as representative medium for mobile components in ecosystems. To assess a more universally valid role of NNP and colloids, an upscaling approach of the catchment based analysis was chosen from regional to national to continental scale.The aim of the regional sampling study was to characterize NNP and colloidal bound P of distinct hydromorphological areas in stream water of the Wüstebach catchment. The NNP and colloidal P could be fractionated in two size fractions (2-20 nm and >20-300 nm), which constituted up to 100% of the total river P discharge depending on hydromorphology. For the small size fraction, variations in P concentrations followed the Al variations; in addition, a high Fe presence in both fractions was accompanied by high P concentrations. Moreover, organic C was approximated together with P in the presence of Fe and Al, suggesting that Fe and Al are potential carriers of P and associated with organic matter. Tracing the origin of NNP and colloid fractions revealed mixed inputs from soil and vegetation of the catchment. The data enables the inputs and source regions of NNP and colloidal fractions to be traced and conceptually defined for the first time within a small river of a headwater catchment. [...]
LB  - PUB:(DE-HGF)11
UR  - https://juser.fz-juelich.de/record/811341
ER  -