title: Dynamics of phosphorus-iron-sulfur at the sediment-water interface influenced by algae blooms decomposition.
abstract: This study addresses the previously unknown effects of algae blooms on the dynamics of phosphorus (P), iron (Fe) and sulfur (S) across a lacustrine sediment-water interface (SWI). A mesocosm experiment was conducted in-situ to investigate these effects based on two recently-developed diffusive gradients in thin-films techniques (DGT). Soluble P, Fe(II), and S(-II) exhibited similar changing trends in a water column subject to the algae addition. Peak concentrations appeared on day 7 of the 16-day experiment. The lowest Eh occurred at the experiment's midway point indicating a strong algae degradation. A maximum increase in DGT-labile S appeared on day 8 near the SWI, while the DGT-labile P and Fe exhibited persistent increases almost to the end of experiment. Significantly positive correlations of labile P were observed switching from between labile Fe and labile S in sediments, suggesting a significant change in original Fe-coupled dynamics of P under algae decomposition. Apparent fluxes were calculated based on DGT profiles where a simultaneous release of P and S occurred from degraded algae, resulting in bidirectional diffusion fluxes from sediment to overlying water. In contrast, sediment acted as a major source of labile Fe due to added depth and apparently positive fluxes.
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Han
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: smding@niglas.ac.cn.
authors.forename: Shiming
authors.initials: S
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Shen
authors.affiliation: School of Civil Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Chungang
authors.initials: C
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Di
authors.initials: D
authors.lastname: Xu
mesh_terms: D000465:Algorithms; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods; D005068:Eutrophication; D019015:Geologic Sediments / Q000032:analysis*; D007501:Iron / Q000737:chemistry*; D060106:Lakes; D008839:Microelectrodes; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D013455:Sulfur; D007501:Iron
keywords: Algae decomposition; Diffusive gradients in thin-films (DGT); Lake taihu; Phosphorus–iron–sulfur (P–Fe–S); Sediment–water interface (SWI)