Response of sediment organic phosphorus composition to lake trophic status in China

Ni, Zhaokui and Wang, Shengrui and Zhang, Bo-Tao and Wang, Yuemin and Li, Hong (2019) Response of sediment organic phosphorus composition to lake trophic status in China. Science of the Total Environment, 652. pp. 495-504. ISSN 0048-9697

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Abstract

Organic phosphorus (Po) constitutes the most important fraction of P in lake sediments, and the compositional properties of Po affect its behavior in lake ecosystems. In this study, 31P NMR, FT-IR spectroscopy, and UV–visible absorbance spectroscopy were combined to identify the dynamic composition of sediment Po across two sets of lakes in China ranging from oligotrophic to eutrophic, and their possible effects on lake eutrophication were evaluated. The results showed that sediment Po content (accounting for 24–75% of TP) was positively correlated with trophic status in both Eastern Plain and Yun-Gui Plateau lakes of China, and the linear relationship was more stable compared to total P (TP), implying that sediment Po may be a superior indicator of trophic status than TP. The Po component, phosphonate accounted for only 0.4% or less of Po, while the monoester P and diester P, accounted for 2–24% and 0.5–5% of Po, respectively, and were the main factors causing Po to increase with the increasing trophic status. The factors were closely related to the enhanced organic sewage load and intensification of contemporary sedimentation of phytoplankton. As trophic status increased, sediment Po might integrate into larger amounts of aromatic substances and functional groups, which could enhance the stability of Po in sediments. Furthermore, sediments from lakes with higher trophic status exhibited a higher degree of humification and molecular weights, which impart resistance to biodegradation, and therefore, reduced the risk of sediment Po release. However, the massive accumulation of bioavailable Po (monoester and diester P) allows possible degradation, supporting algal growth and maintains eutrophic status because there is abundant alkaline phosphatase in eutrophic lakes. Thus, to control lake eutrophication more effectively, targeted actions are urgently required to reduce the accumulation and degradation of Po in lake sediment.

Item Type:
Journal Article
Journal or Publication Title:
Science of the Total Environment
Additional Information:
This is the author’s version of a work that was accepted for publication in Science of the Total Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Science of the Total Environment, 652, 2019 DOI: 10.1016/j.scitotenv.2018.10.233
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2300/2311
Subjects:
ID Code:
129312
Deposited By:
Deposited On:
20 Dec 2018 11:05
Refereed?:
Yes
Published?:
Published
Last Modified:
28 Oct 2020 07:00