Preferential regeneration of P relative to C in a freshwater lake. (May 2019)

• Record Type: Journal Article
• Authors: Chen, Jingan; Zeng, Yan; Yu, Jia; Wang, Jingfu; Yang, Haiquan; Lu, Yaoting
• Is Part Of: Chemosphere. Volume 222(2019)
• Page Start: 15
• Page End: 21
• Publication Date: 2019-05
• Subjects: P regeneration -- TOC/P ratio -- Suspended particulate matter -- Sediment -- Hongfeng Lake; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.01.088
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Particulate organic matter (POM) is the main carrier of carbon (C), nitrogen (N), and phosphorus (P) in the biogeochemical cycle. Previous investigations have found that the regeneration of C, N, and P is obviously different during the degradation of POM in marine environments. However, little attention has been paid to lake system thus far. In an initial attempt to characterize the regeneration behaviors of C and P in lake system, contents of C, N, and P in suspended particulate matter (SPM) and surface sediments of Hongfeng Lake were systematically investigated in this study. The results showed that the total organic carbon (TOC) to total phosphorus (TP) ratios (TOC/P) were obviously lower in SPM than in surface sediments, which demonstrated the preferential regeneration of P relative to C in lake system for the first time. Possible mechanisms for such include reductive dissolution of Fe oxyhydroxide and poly-P remineralization under hypoxic/anoxic conditions. Based on the difference in the TOC/P ratios between SPM and surface sediments, about 25.1 t P was estimated to be released annually from settling seston and sediments in Hongfeng Lake, which is much higher than the previous results on the P release flux from sediment. This indicates that a significant percentage of P may be regenerated during particulate matter transport in the water column, providing new insight into the P regeneration in lake system. The preferential regeneration of P may result in a positive feedback loop among bottom water anoxia, enhanced P regeneration, and algal bloom in sub-deep lakes. Highlights: TOC/P ratios are lower in SPM than surface sediments. The preferential regeneration of P relative to C occurs in lake system. A significant percentage of P may be regenerated during seston transportation. A positive feedback loop exists among water anoxia, P regeneration and algal bloom.