Organic phosphorus regeneration enhanced since eutrophication occurred in the sub-deep reservoir. (1st August 2022)

• Record Type: Journal Article
• Authors: Yu, Jia; Zeng, Yan; Chen, Jingan; Liao, Peng; Yang, Haiquan; Yin, Chao
• Is Part Of: Environmental pollution. Volume 306(2022)
• Publication Date: 2022-08-01
• Subjects: Eutrophication -- Sub-deep lake -- Organic phosphorus -- Organic matter degradation -- C/P ratios; 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.2022.119350
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Lake eutrophication remains a serious environmental problem of global significance, and phosphorus (P) plays a key role in lake eutrophication. Internal P loading, as a result of P release from sediments, is gathering more and more recognition as an important source governing the P availability in these ecosystems. Anoxic condition can promote the release of P associated with Fe oxides, which has already been a consensus. However, it is still unknown whether the anoxic conditions induced by eutrophication act to intensify or weaken the regeneration of organic P (Porg ) in sediments. We selected the Hongfeng Reservoir, a typical sub-deep lake, to study the regeneration behaviours of C and P in the sediments buried before and after eutrophication. The results showed that Porg did not significantly increase with the rapid increase in organic C (Corg ) since eutrophication occurred. Furthermore, the organic C/P ratio was much higher in sediments buried after eutrophication than in those buried before, which indicated that Porg regeneration had been significantly enhanced since eutrophication occurred. Based on C/P ratios, our estimation suggested that the Porg regeneration and P release from sediment to water approximately enhanced 45.2% ± 8.7% and 34.5% ± 9.8%, respectively. Elevated primary productivity (algae) and the corresponding hypoxic/anoxic condition, both caused by eutrophication, promoted P biogeochemical cycle in the sub-deep reservoir. This study further verifies the significant contribution of regenerated Porg to the internal P load, and highlights the importance of controlling P release from sediments in order to restore clear water ecosystems in sub-deep lakes or reservoirs. Graphical abstract: Image 1 Highlights: Organic C/P ratio of lake sediments became much higher after eutrophication. Organic P regeneration had been enhanced by 45.2% since eutrophication occurred. Sediment P release proportion increased 34.5% after eutrophication.