Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1002/lno.12046 |
Licence  |
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| Title (Primary) | Measurement of microplastic settling velocities and implications for residence times in thermally stratified lakes |
| Author | Elagami, H.; Ahmadi, P.; Fleckenstein, J.H.; Frei, S.; Obst, M.; Agarwal, S.; Gilfedder, B.S. |
| Source Titel | Limnology and Oceanography |
| Year | 2022 |
| Department | HDG |
| Volume | 67 |
| Issue | 4 |
| Page From | 934 |
| Page To | 945 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Supplements | https://aslopubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Flno.12046&file=lno12046-sup-0001-supinfo.docx |
| UFZ wide themes | Microplastics; |
| Abstract | Microplastics residence times in lakes are currently poorly understood. In this work, settling experiments with pristine and biofilm-colonized microplastic particles were combined with model calculations to evaluate settling velocities, particle distributions, and residence times in the epilimnion, metalimnion, and hypolimnion of a hypothetical stratified lake broadly based on Upper Lake Constance. Settling velocities of various biodegradable and nonbiodegradable polymers of various shapes, sizes, and biofilm colonization were measured in a settling column. The settling velocities ranged between ~ 0.30 and ~ 50 mm s−1. Particle sizes and polymer densities were identified as primary controls on settling rates. Microplastic particles that had been exposed to a lake environment for up to 30 weeks were colonized by a range of biofilms and associated extracellular polymeric substances; surprisingly, however, the settling velocity did not vary significantly between pristine and colonized microplastic particles. Simulated microplastic residence times in the model lake varied over a wide range of time scales (10−1 to 105 d) and depended mainly on the size of the particles and depth of the lake layer. Long residence times on the order of 105 d (for 1-μm microplastic particles) imply that for small microplastic particles there is a high probability that they will be taken up at some stage by lake organisms. As the lake retention time (~ 4.5 years) is considerably shorter than the residence time of small microplastics, negligible quantities of these microplastic particles should be found in the lake sediment unless some other process increases their settling velocity. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=25830 |
| Elagami, H., Ahmadi, P., Fleckenstein, J.H., Frei, S., Obst, M., Agarwal, S., Gilfedder, B.S. (2022): Measurement of microplastic settling velocities and implications for residence times in thermally stratified lakes Limnol. Oceanogr. 67 (4), 934 - 945 10.1002/lno.12046 |
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