State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Sci Total Environ. 2020 Jun 25;723:137872. doi: 10.1016/j.scitotenv.2020.137872. Epub 2020 Mar 24.
Sediment bulking is intently related to the occurrence of black water agglomerate, sediment resuspension and erosion in aquatic environments. In this study, five different lake sediments were sampled to study effects of sediment characteristics on sediment bulking and then investigate how sediment bulking affected in turn sediment physicochemical properties. Within 30 days of experiments, the sediment properties showed an obvious influence on variation in sediment height (VSH) ranging from only 0.03 to 1.26 cm for five sediment samples. It was found that labile nutrients were closely related to the VSH (P < 0.05) during sediment bulking. In addition, the high-throughput sequencing revealed that the microbial communities in sediments associated with degradation of organic matter and anaerobic environments, were also related to sediment bulking. Through comparing sediments with and without bulking, it was found that sediment bulking would clearly increase the proportion of air around 2.14 times, and reduce the critical shear stress of sediment with a decrease by 67.33% after 30 days, which favored sediment resuspension and erosion. Thus, this study could provide a deep insight in the key factors and the environmental effects of sediment bulking, and then be helpful in protecting the aquatic environments against ecological disasters.
底泥膨淤与水体中黑团块的出现、底泥再悬浮和侵蚀密切相关。本研究采集了五种不同的湖泊沉积物，以研究沉积物特性对底泥膨淤的影响，进而探讨底泥膨淤如何反过来影响沉积物的理化性质。在 30 天的实验中，五种沉积物的性质对底泥高度变化（VSH）的影响明显，范围从仅 0.03 到 1.26 厘米。结果发现，在底泥膨淤过程中，活性养分与 VSH 密切相关（P<0.05）。此外，高通量测序结果表明，与有机质降解和厌氧环境相关的沉积物中的微生物群落也与底泥膨淤有关。通过比较膨淤和未膨淤的沉积物，发现膨淤后 30 天，沉积物中空气的比例明显增加了 2.14 倍，沉积物的临界剪切应力降低了 67.33%，这有利于底泥的再悬浮和侵蚀。因此，本研究可以深入了解底泥膨淤的关键因素及其对环境的影响，从而有助于保护水生态系统免受生态灾害。
