Liu Guo-Feng, He Jun, Fan Cheng-Xin, Zhang Lei, Shen Qiu-Shi, Zhong Ji-Cheng, Yan Shao-Hua
State Key Laboratory of Lake & Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Huan Jing Ke Xue. 2010 Nov;31(11):2652-60.
The driving effects of algal cells settlement in the water-sediment interface on Fe, Mn, S biogeochemistry in laboratory through static cultivation device. Results showed that dissolved oxygen would be exhausted by algae cells in 50 min after the cyanobacteria cells settled to the sediment surface. Soon the water-sediment interface formed the severe anoxia and Fe-Mn oxides and sulfides were deoxidized quickly in the strong reducing environment. The Fe2+, Mn2+ content in interface increased to the summit at the 4th day and their concentrations were 4.40 mg/L and 2.35 mg/L, respectively. When it comes to the end of the experiment, the Fe2+ content had a little reduction and Mn2+ reduced quickly, their concentrations were 3.37 mg/L and 0.97 mg/L at the end of experiment. However, S2- concentration in interface reached the highest at the 2nd day and its content was 0.63 mg/L, and its concentration was only 0.12 mg/L at the end since it has been reduced. The ORP was--150 mV in the sediment surface and indicated that the sediment environment was a strong reducing environment. Phenomenon of algal cells induced black spots in water bodies was the main driving factors on Fe/Mn oxides and sulfides biogeochemistry cycle, and also the extreme anoxia environment would have great harm on the water body's ecology.
通过静态培养装置研究藻细胞沉降在水-沉积物界面中对铁、锰、硫生物地球化学的驱动作用。结果表明，蓝藻细胞沉降至沉积物表面50分钟后，藻细胞会耗尽溶解氧。很快水-沉积物界面形成严重缺氧状态，铁-锰氧化物和硫化物在强还原环境中迅速被还原。界面处Fe2+、Mn2+含量在第4天达到峰值，其浓度分别为4.40mg/L和2.35mg/L。到实验结束时，Fe2+含量略有下降，Mn2+迅速降低，实验结束时其浓度分别为3.37mg/L和0.97mg/L。然而，界面处S2-浓度在第2天达到最高，含量为0.63mg/L，由于其被还原，实验结束时浓度仅为0.12mg/L。沉积物表面的氧化还原电位为-150mV，表明沉积物环境为强还原环境。藻细胞诱导水体中出现黑斑的现象是铁/锰氧化物和硫化物生物地球化学循环的主要驱动因素，而且极端缺氧环境会对水体生态造成极大危害。
