Implications of phosphorus partitioning at the suspended particle-water interface for lake eutrophication in China's largest freshwater lake, Poyang Lake. (January 2021)

• Record Type: Journal Article
• Authors: Pu, Jia; Wang, Shengrui; Ni, Zhaokui; Wu, Yue; Liu, Xiaofei; Wu, Tao; Wu, Huaxin
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Total dissolved phosphorus (TDP) -- Soluble reactive phosphorus (SRP) -- Turbulence intensity -- Partition coefficient -- Lake eutrophication; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128334
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Nutrient partition, especially for phosphorus (P), has been prominently changed that was caused by variation of river-lake relationship during the post-Three Gorges Reservoir and catchment alternations. Changes in proportion of total particulate phosphorus (TPP) and total dissolved phosphorus (TDP) might accelerate lake eutrophication, but limited attention has been paid to P partition over suspended particle (SP) levels. Data analysis showed that SP concentration presented a positive effect on TPP in wet season and soluble reactive phosphorus (SRP) in dry season, indicating seasonal physical and chemical variations. Based on this phenomenon, we proposed a hypothesis that the SP levels would affect TDP and TPP proportions by partition in aqueous-solid. It was found that using the parabola models to fit the sorption relationships of SRP and TDP (R 2 > 0.6, p < 0.01), the maximum sorption capacity (Qmax ) was 64.54 mg/kg and 60.52 mg/kg at 400 mg/L of SP level, respectively. In addition, the partition coefficients (KP ) of TDP and SRP were logarithmically increased with SP levels, indicating that higher SP levels (>400 mg/L) would hinder the sorption process. Furthermore, enhancing turbulence lead to less sorption of SRP and TDP at high SP levels (>800 mg/L). The sorption of SRP and TDP related to the presence of Fe/Al oxy-hydroxides were enriched in the Fe/Al–P fraction (47% of TP). The findings of this study indicated that the low SP levels would increase P bioavailability for alga and is not conducive for lake eutrophication management. Graphical abstract: Image 1 Highlights: Suspended particle (SP) was positively related to the concentrations of TPP and SRP in wet and dry season, respectively. Phosphorus (P) sorption capacity was not synergistic with SP levels. Increasing turbulence hindered the adsorption of dissolved phosphorus (TDP, SRP) at high SP levels. Fe/Al–P was the primary form of bioavailable P and a determinant of the sorption potential SP for P. Low SP levels partitioned more TDP (SRP) in water and contributed to alga bloom and lake eutrophication.