Negative impacts of nanoplastics on the purification function of submerged plants in constructed wetlands: Responses of oxidative stress and metabolic processes.
Water Res
; 227: 119339, 2022 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-36371921
ABSTRACT
Constructed wetlands (CWs) are an important barrier to prevent nanoplastics (NPs) and microplastics (MPs) from entering receiving streams. However, little is known about how the accumulation of NPs affects the growth, photosynthesis, oxidative stress responses, and metabolism of plants, especially submerged plants that are widely used in CWs for water purification. Herein, we adopted Utricularia vulgaris (U. vulgaris), a typical submerged macrophyte as the model plant to address the above knowledge gaps under exposure to polystyrene NPs (PS-NPs, 500 nm, 0â¼10 mg·L-1). Results showed that PS-NPs were absorbed by insect traps and further transported to stems and leaves of U. vulgaris, which limited plant height (6.8â¼72.9%), relative growth rate (7.4â¼17.2%), and photosynthesis (3.7â¼28.2%). U. vulgaris suffered from oxidative stresses, as evidenced by the increase in malondialdehyde, antioxidant enzymes (catalase, peroxidase, and superoxide dismutase), and H2O2, especially under 1 and 10 mg·L-1. Abundances of 548 metabolites were quantified, and 291 metabolites were detected with altered levels after exposure, in which 25â¼34% metabolites were up-regulated, and 32â¼40% metabolites were down-regulated in metabolite expression. Metabolic pathways of the tricarboxylic acid cycle and amino acid were disrupted, in which citric acid, threonine, and adenine decreased, while amino acids (like serine, phenylalanine, histidine, etc.) increased first and then decreased with increasing PS-NPs concentrations. Moreover, PS-NPs reduced the removal efficiency of total nitrogen and phosphorus from water by U. vulgaris, bringing potential risks to aquatic ecosystems. These findings have greatly enhanced our understanding of the metabolic mechanisms and interactions of aquatic macrophytes that are heavily used in CWs in response to NPs stress, as well as the impact of NPs on CWs functioning.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Microplásticos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Water Res
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China