On Aug.18, the article titled “Diffusion and filamentous bacteria jointly govern the spatiotemporal process of sulfide removal in sediment microbial fuel cells” was published by Chemical Engineering Journal. Postdoctor Wang Bin and graduate student Zhang Heng in Guangdong Institute of Microbiology are the co-first authors, Prof. Yang Yonggang and Prof. Xu Meiying are the co-corresponding authors of this article.
Remediation of black-odorous water environments is one of the most important challenges in the environment protection in China. High concentration of sulfides is the main reason causing black-odorous water and microbial extracellular electron transfer (EET) is an efficient way to remove those harmful sulfides. Therefore, addition of favorable extracellular electron donors is promising for the remediation of black-odorous rivers. In this article, the authors used graphite electrodes to stimulate the EET in black-odorous sediments and archived highly efficient sulfides removal. Micro-sensor measurement showed that the sulfide, pH, total organic carbon decreased toward the electrode surface while redox potential and SO42- increased. The effected sphere of electrode expanded along with time and current density. Microbial community and scanning electronic microscope analyses showed that the geochemical gradients toward electrode caused enrichment of several filamentous bacteria as keystones. These filamentous bacteria formed microbial networks around electrode which can stimulate the environment homogenization and sulfides removal in sediments. Therefore, the article proposes that driven by the EET, diffusion and filamentous bacteria jointly dominate the spatiotemporal processes of sediment sulfide removal. The results not only provide necessary guide for developing techniques for remediation of black-odorous, but also provide important information for realize the environmental effects of microbial EET in various environments.
This work was funded by the National Natural Science Foundation of China and GDAS’ Special Project of Science and Technology Development.