Zhang Yihui, Hu Weiping, Hu Yuemin
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Feb 23. doi: 10.1007/s11356-021-12889-8.
Internal loadings of nutrients play important roles in the eutrophication of shallow lakes. The effective removal of sediments rich in nutrients is of great importance for lake management and the abatement of eutrophication. In this study, grooves were installed in the bottom of Lake Chaohu. Approximately 8.5 months later, the chlorophyll a, organic matter, and total nitrogen contents in the sediment inside the grooves were 1.5-3.0 times, 1.2-1.8 times, and 1.3-1.6 times higher, respectively, than those in the surrounding sediments, and the total phosphorus contents in the bottom grooves were slightly lower than those in the surrounding sediments. The thicknesses of the sediments with high chlorophyll a, organic matter, total nitrogen, and total phosphorus contents in the grooves were 5-15 times greater than those of the surrounding sediments with high pollution contents. Internal pollution was captured in the grooves. The active hydrodynamic process was an important factor related to the effectiveness of this method and is conducive to the transport of polluted sediments to the bottom grooves where they are collected. Bottom grooves have broad application potential for the removal of sediments rich in nutrients from shallow-water lakes; these grooves can be widely used in areas that experience large disturbances from wind waves, have water flows gathering in or entering the lake, or have thin sediments with high pollution contents. This study provides scientific guidance for the control and management of internal pollution in shallow lakes.
营养物质的内源负荷在浅水湖泊富营养化过程中起着重要作用。有效去除富含营养物质的沉积物对于湖泊管理和富营养化治理至关重要。在本研究中，在巢湖底部设置了凹槽。大约8.5个月后，凹槽内沉积物中的叶绿素a、有机质和总氮含量分别比周围沉积物高1.5 - 3.0倍、1.2 - 1.8倍和1.3 - 1.6倍，底部凹槽中的总磷含量略低于周围沉积物。凹槽中叶绿素a、有机质、总氮和总磷含量高的沉积物厚度比周围污染含量高的沉积物厚5 - 15倍。内源污染被捕获在凹槽中。活跃的水动力过程是与该方法有效性相关的重要因素，有利于将污染沉积物输送到底部凹槽进行收集。底部凹槽在去除浅水湖泊中富含营养物质的沉积物方面具有广阔的应用潜力；这些凹槽可广泛应用于风浪扰动大、有水流汇入或进入湖泊、或沉积物薄且污染含量高的区域。本研究为浅水湖泊内源污染的控制和管理提供了科学指导。
