A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Optimized and Validated Settling Velocity Measurement for Small Microplastic Particles (10–400 μm)
https://orcid.org/0000-0002-6720-7095
https://orcid.org/0000-0002-2443-4722
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 μm) 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 suspensionsespecially 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 μm) 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.
This study presents and validates a method for measuring the settling velocities of small microplastics (10−400 μm) and successfully addresses potential disruptive factors such as convection or particle−particle interactions.
Optimized and Validated Settling Velocity Measurement for Small Microplastic Particles (10–400 μm)
https://orcid.org/0000-0002-6720-7095
https://orcid.org/0000-0002-2443-4722
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 μm) 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 suspensionsespecially 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 μm) 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.
This study presents and validates a method for measuring the settling velocities of small microplastics (10−400 μm) and successfully addresses potential disruptive factors such as convection or particle−particle interactions.
Optimized and Validated Settling Velocity Measurement for Small Microplastic Particles (10–400 μm)
https://orcid.org/0000-0002-6720-7095
https://orcid.org/0000-0002-2443-4722
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 μm) 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 suspensionsespecially 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 μm) 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.
This study presents and validates a method for measuring the settling velocities of small microplastics (10−400 μm) and successfully addresses potential disruptive factors such as convection or particle−particle interactions.
Optimized and Validated Settling Velocity Measurement for Small Microplastic Particles (10–400 μm)
Dittmar, Stefan (author) / Ruhl, Aki S. (author) / Jekel, Martin (author)
ACS ES&T Water ; 3 ; 4056-4065
2023-12-08
Article (Journal)
Electronic Resource
English
Settling Velocity of Porous Spherical Particles
| ASCE | 2019
Settling Velocity of Spherical Particles in Calm Water
| ASCE | 2021
Settling and Rising Hydrodynamics of Microplastic Pollutants: A Numerical Study
| Springer Verlag | 2023
Settling velocity of irregularly shaped particles in Newtonian fluids
| Taylor & Francis Verlag | 2013
Effect of Concentration on Settling Velocity of Sediment Particles
| Online Contents | 1997