State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China.
Department of Environmental Science, China Pharmaceutical University, Nanjing 211198, PR China.
J Hazard Mater. 2014 Feb 15;266:1-9. doi: 10.1016/j.jhazmat.2013.12.008. Epub 2013 Dec 12.
Flocculation is a promising method for controlling harmful algal blooms; however, little is known about the effects of algae deposition by flocculation on benthic oxygen (O2) and nutrient dynamics. In this study, we aimed to investigate the influence of cyanobacteria flocculation deposition on benthic O2 and phosphorus (P) dynamics and the role of tubificid worms in the process. Chitosan and sediment particles were used to flocculate and deposit cyanobacteria cells onto lake sediment. The impulse deposition of algal flocculation degraded the deposited algal cells, which decreased the O2 penetration depth in sediment and increased the O2 uptake rate. Algae deposition also increased the soluble reactive P (SRP) in pore water and loosely adsorbed P in sediment, and changed SRP flux. Tubificid worms transported algal cells deeper into the sediment, mitigated their degradation, and altered the O2 penetration depth, but not the O2 uptake rate. Tubificid worms enhanced the increase in pore-water SRP and loosely adsorbed P in sediment. Therefore, the deposition of algal flocculation modifies the benthic O2 and P dynamics, and tubificid worms can mitigate or enhance some of these processes.
絮凝是控制有害藻类水华的一种很有前途的方法；然而，对于絮凝引起的藻类沉积对底栖氧（O2）和养分动态的影响知之甚少。在这项研究中，我们旨在研究蓝藻絮凝沉积对底栖 O2 和磷（P）动态的影响，以及多毛环节动物在该过程中的作用。壳聚糖和沉积物颗粒被用来絮凝和将蓝藻细胞沉积到湖底沉积物上。藻类絮凝的脉冲沉积使沉积的藻类细胞降解，从而降低了沉积物中 O2 的穿透深度，并增加了 O2 的吸收速率。藻类沉积还增加了孔隙水中的可溶性反应磷（SRP）和沉积物中松散吸附的磷，改变了 SRP 通量。颤蚓将藻类细胞更深地输送到沉积物中，减轻了它们的降解，并改变了 O2 的穿透深度，但不改变 O2 的吸收速率。颤蚓增强了孔隙水中 SRP 和沉积物中松散吸附磷的增加。因此，藻类絮凝的沉积改变了底栖 O2 和 P 的动态，而颤蚓可以减轻或增强其中的一些过程。
