Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
J Environ Manage. 2023 Aug 15;340:118016. doi: 10.1016/j.jenvman.2023.118016. Epub 2023 Apr 28.
Identifying phosphorus (P) sources and contributions from terrestrial sources is important for clean water and eutrophication management in lake watersheds. However, this remains challenging owing to the high complexity of P transport processes. The concentrations of different P fractions in the soils and sediments from Taihu Lake, a representative freshwater lake watershed, were obtained using sequential extraction procedure. The dissolved phosphate (PO-P) and alkaline phosphatase activity (APA) in the lake's water were also surveyed. The results showed that different P pools in the soil and sediments displayed different ranges. Higher concentrations of P fractions were measured in the solid soils and sediments from the northern and western regions of the lake watershed, indicating a larger input of P from exogenous sources, including agriculture runoff and industrial effluent from the river. Generally, higher Fe-P and Ca-P concentrations of up to 399.5 and 481.4 mg/kg were detected in soils and lake sediments, respectively. Similarly, the lake's water had higher concentrations of PO-P and APA in the northern region. A significant positive correlation was found between Fe-P in the soil and PO-P concentrations in the water. Statistical analysis indicated that appropriately 68.75% P was retained in the sediment from terrigenous sources, and 31.25% P experienced dissolution and shifted to the solution phase in the water-sediment ecosystems. The dissolution and release in Fe-P in the soils were responsible for the increase of Ca-P in the sediment after the afflux of soils into the lake. These findings suggest that soil runoff predominantly controls P occurrence in lake sediments as an exogenous source. Generally, the strategy of reducing terrestrial inputs from agricultural soil discharge is still an important step in P management at the catchment scale of lakes.
确定磷（P）的来源和陆地来源的贡献对于湖泊流域的清洁水和富营养化管理很重要。然而，由于 P 运输过程的高度复杂性，这仍然具有挑战性。使用连续提取程序获得了太湖流域代表淡水湖泊流域土壤和沉积物中不同 P 分数的浓度。还调查了湖泊水中溶解磷酸盐（PO-P）和碱性磷酸酶活性（APA）。结果表明，土壤和沉积物中的不同 P 池具有不同的范围。湖泊流域北部和西部土壤和沉积物中测量到较高浓度的 P 分数，表明外源 P 的输入较大，包括农业径流和河流工业废水。通常，在土壤和湖泊沉积物中分别检测到高达 399.5 和 481.4 mg/kg 的较高 Fe-P 和 Ca-P 浓度。同样，湖泊水中北部区域的 PO-P 和 APA 浓度较高。土壤中的 Fe-P 与水中的 PO-P 浓度之间存在显著正相关。统计分析表明，约 68.75%来自陆源的 P 保留在沉积物中，31.25% P 溶解并转移到水-沉积物生态系统的溶液相中。土壤中 Fe-P 的溶解和释放是土壤流入湖泊后沉积物中 Ca-P 增加的原因。这些发现表明，土壤径流主要控制着作为外源的湖泊沉积物中的 P 发生。通常，减少农业土壤排放的陆地输入的策略仍然是湖泊流域 P 管理的重要步骤。
