Microplastic Impacts on Microalgae Growth: Effects of Size and Humic Acid
| Autor: | Eddy Y. Zeng, Ge Liu, Jing You, Ruifen Jiang, Derek C. G. Muir |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
congenital hereditary and neonatal diseases and abnormalities Microplastics Chemistry nutritional and metabolic diseases General Chemistry 010501 environmental sciences Photosynthesis 01 natural sciences Cell wall Environmental chemistry Toxicity Dissolved organic carbon Microalgae Environmental Chemistry Humic acid Particle size Surface charge skin and connective tissue diseases Plastics Humic Substances Water Pollutants Chemical 0105 earth and related environmental sciences |
| Zdroj: | Environmental Science & Technology. 54:1782-1789 |
| ISSN: | 1520-5851 0013-936X |
| Popis: | Research has already demonstrated the toxic effects of microplastics (MPs) on different biota. However, the underlying toxic mechanism of MPs remains to be elucidated, especially the effect of particle size and the presence of dissolved organic matter in water. This study investigated the impact on Scenedesmus obliquus exposed in five types of polystyrene particle suspensions with different sizes and surface charges, in the presence and absence of humic acid (HA). Results indicated that the 50% growth inhibition rate of S. obliquus showed no significant difference between the five types of MPs, but the toxic mechanism varied with particle size. Larger size MPs caused adverse effects by blocking the light transport and affecting photosynthesis, while smaller ones destroyed the cell wall by adsorbing onto the algae surface. Also, the addition of HA significantly alleviated the toxicity of smaller size MPs, but not of the larger ones. Scanning electron microscopy images and the reactive oxygen species assay demonstrated that the HA could form a corona on the surface of MPs, reduce the affinity to microalgae, and minimize the adverse effect. Together, these findings identified important factors in determining the toxicity of MPs, providing valuable data for risk assessment of MPs. |
| Databáze: | OpenAIRE |
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