Photo-induced phosphate release during sediment resuspension in shallow lakes: A potential positive feedback mechanism of eutrophication. (March 2020)

• Record Type: Journal Article
• Authors: Guo, Minli; Li, Xiaolu; Song, Chunlei; Liu, Guanglong; Zhou, Yiyong
• Is Part Of: Environmental pollution. Volume 258(2020)
• Publication Date: 2020-03
• Subjects: Phosphate -- Sediment -- Organic phosphorus -- Photo-release -- Eutrophication; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113679
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Dissolved phosphate (Pi ) can be released during resuspended sediments exposed to sunlight. However, the significance of this phenomenon in the process of eutrophication is not clear. In this study, the behavior of photo-induced Pi release during sediment resuspension in shallow lakes with the different trophic states was investigated. The amount of photo-induced Pi release in the sediment resuspension from Lake Liangzi, Lake Dong, Lake Tangxun and Lake Longyang in China was 0.013, 0.019, 0.032, and 0.048 mg/L, respectively, and increased as the trophic states of the lakes increased. The results of phosphorus speciation analysis showed that the phosphate monoester in the particulate phosphorus is the organic phosphorus species participated in the photochemical reaction. The steady-state concentration of hydroxyl radical (OH) in the sediment resuspension also increased along with the trophic states of lakes increased and dissolved organic matter (DOM), nitrate, and Fe 3+ presented in sediment resuspension were the main photosensitizers for OH production. All these results indicate that the increase of trophic states of lakes leads to the accumulation of organic phosphorus and OH, resulting in more dissolved phosphate photo-released, which accelerate the eutrophication process in a form of positive feedback. Graphical abstract: Image 1 Highlights: The amount of photo-induced Pi release increases as trophic states of shallow lakes increases. The accumulation of Po in shallow lakes is source for the photo-induced Pi release. .OH generated by natural photosensitizers is driving force for the photo-induced Pi release. Photo-induced Pi release is a potential positive feedback mechanism of eutrophication. Abstract : This work found that the amount of photo-induced phosphate release during sediment resuspension increased as the trophic states of lakes increased.