Vorschaubild nicht verfügbar
Publikationstyp
Wissenschaftlicher Artikel
Erscheinungsjahr
2023
Optimized and validated settling velocity measurement for small microplastic particles (10-400 My m)
Optimized and validated settling velocity measurement for small microplastic particles (10-400 My m)
Autor:innen
Herausgeber
Quelle
ACS ES & T water / American Chemical Society
3 (2023), Heft 12
3 (2023), Heft 12
Schlagwörter
Verkehr
Zitation
DITTMAR, Stefan, Martin JEKEL und Aki Sebastian RUHL, 2023. Optimized and validated settling velocity measurement for small microplastic particles (10-400 My m). ACS ES & T water / American Chemical Society [online]. 2023. Bd. 3 (2023), Heft 12. DOI 10.60810/openumwelt-1052. Verfügbar unter: https://openumwelt.de/handle/123456789/1191
Zusammenfassung englisch
The settling velocity of nonbuoyant microplastics is one of the key parameters to describe their vertical transport in water, yet it has rarely been studied for small microplastics (<500 My m) thus far. Respective measurements are challenging as they are prone to disruptive factors such as thermal convection. With decreasing size, it also becomes more difficult to handle target particles separately. Instead, it is favorable to work with suspensions-especially when characterizing particle populations based on sufficient individual measurements. This study establishes and validates a suitable measuring setup, which mainly consists of a precisely tempered settling column that is monitored via optical imaging with subsequent particle tracking. Comprehensive validation experiments with different spherical particles covering the desired size (10-388 My m) and density range (1.05-2.46 g/cm3) verify exceptionally high measurement accuracy and precision. Different investigation schemes were proposed and successfully tested for polydisperse and monodisperse particle samples, respectively. At elevated particle doses, measured settling velocities increased due to swarm effects and interactions between particles. A novel empirical model was fitted to represent those effects. The model can aid in limiting the particle dosage and thus prevent overestimations of single particle velocities. © 2023 The Authors