School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China.
School of Hydraulic Energy and Power Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China.
Environ Sci Pollut Res Int. 2019 Oct;26(30):31392-31400. doi: 10.1007/s11356-019-06291-8. Epub 2019 Aug 31.
Tetrabromobisphenol A (TBBPA) is an emerging contaminant and exists widely in river and lake systems due to its widespread use. In natural water-sediment systems, hydrodynamic disturbances always exist. However, few studies have investigated the mechanism of TBBPA biodegradation under the influence of water disturbances. In this paper, using a specialized type of racetrack-style flumes, the TBBPA biodegradation in water-sediment systems was studied under the influence of three typical hydrodynamic disturbances. The results of 5-week experiments showed that strong hydrodynamic disturbances greatly accelerate the TBBPA biodegradation rate of the water-sediment systems. The half-lives (T) under static condition (SC) were approximately 40.2 days, and the T was reduced to 16.0 days under strong hydrodynamic condition (SHC). Furthermore, the physicochemical properties and corresponding bacterial communities under these conditions were investigated to help explain the TBBPA biodegradation mechanism. The results showed that strong currents could promote dissolved oxygen (DO) levels, increase nutrient concentrations, and reduce the bacterial diversity in the sediment. Meanwhile, due to the increase in DO and nutrient concentrations, the aerobic bacterial genera conducting TBBPA biodegradation showed rapid growth with strong water disturbances, while the growth of anaerobic bacterial genera was inhibited. Citrobacter, which was the most dominant degrading bacterial genus (0.6%-14.9% in water and 3.5%-17.4% in sediment), was closely related to water disturbances and may be linked to enhanced TBBPA biodegradation. Other minor degrading bacterial genera, such as Bacillus, Sphingomonas, Anaeromyxobacter, Geobacter, Clostridium, and Flavobacterium, were also found in these water-sediment systems. The findings from this study showed the importance of considering hydrodynamic disturbance in understanding TBBPA biodegradation in aquatic environments.
四溴双酚 A（TBBPA）是一种新兴的污染物，由于其广泛的应用，广泛存在于河流和湖泊系统中。在自然水-沉积物系统中，水动力干扰总是存在的。然而，很少有研究探讨在水动力干扰影响下 TBBPA 生物降解的机制。在本文中，使用一种特殊类型的椭圆形水槽，研究了三种典型水动力干扰下的水-沉积物系统中 TBBPA 的生物降解。为期 5 周的实验结果表明，强烈的水动力干扰大大加速了水-沉积物系统中 TBBPA 的生物降解速率。在静态条件（SC）下的半衰期（T）约为 40.2 天，而在强水动力条件（SHC）下 T 减少至 16.0 天。此外，还研究了这些条件下的物理化学性质和相应的细菌群落，以帮助解释 TBBPA 生物降解机制。结果表明，强水流可以促进溶解氧（DO）水平的提高，增加营养物质浓度，并降低沉积物中的细菌多样性。同时，由于 DO 和营养物质浓度的增加，进行 TBBPA 生物降解的好氧细菌属快速生长，而厌氧细菌属的生长受到抑制。与水动力干扰密切相关并可能与增强的 TBBPA 生物降解有关的优势降解细菌属是柠檬酸杆菌（Citrobacter），其在水中的丰度为 0.6%-14.9%，在沉积物中的丰度为 3.5%-17.4%。其他次要的降解细菌属，如芽孢杆菌属（Bacillus）、鞘氨醇单胞菌属（Sphingomonas）、厌氧单胞菌属（Anaeromyxobacter）、地杆菌属（Geobacter）、梭菌属（Clostridium）和黄杆菌属（Flavobacterium），也存在于这些水-沉积物系统中。本研究的结果表明，在理解水生环境中 TBBPA 生物降解时，考虑水动力干扰的重要性。
