Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
Environ Res. 2021 Oct;201:111572. doi: 10.1016/j.envres.2021.111572. Epub 2021 Jun 27.
Improving the buffer capacity of the electrolyte can enhance the anode performance in bioelectrochemical systems (BESs). To elucidate the mechanism underlying the facilitated BESs performance, this study used three different anode biofilms cultured with different concentrations of phosphate buffer (5, 50 and 100 mM) to investigate the biofilm response, in terms of the spatial structure of metabolic activity and microbial community, to different buffer capacities. Results showed that the electrochemical activities of the anode biofilms positively correlated with the buffer concentration. The spatial stratification of metabolic activity and microbial community of the anode biofilms were regulated by the buffer capacity, and the spatial microbial heterogeneity of the anode biofilm decreased as the buffer concentration increased. With increasing buffer capacity, Geobacter spp. were enriched in both the inner and outer layers of the biofilm, and the inhibition of methanogens growth improved the COD removal attributed to anode respiration. Additionally, the stimulation of EPS production in biofilms played a role in increasing the electrochemical performance of biofilms by buffer improvement. This study first revealed the regulation of buffer capacity on the stratification of anode biofilm during brewery wastewater treatment, which provided a deep insight into the relation of biofilm structure to its electrochemical properties.
提高电解液的缓冲能力可以增强生物电化学系统（BES）中的阳极性能。为了阐明促进 BES 性能的机制，本研究使用三种不同浓度磷酸盐缓冲液（5、50 和 100 mM）培养的三种不同阳极生物膜，研究了生物膜对不同缓冲能力的反应，包括代谢活性和微生物群落的空间结构。结果表明，阳极生物膜的电化学活性与缓冲浓度呈正相关。阳极生物膜代谢活性和微生物群落的空间分层受缓冲能力调节，随着缓冲浓度的增加，阳极生物膜的空间微生物异质性降低。随着缓冲能力的增加，Geobacter spp. 在生物膜的内外层中都得到了富集，并且抑制产甲烷菌的生长提高了归因于阳极呼吸的 COD 去除率。此外，生物膜中 EPS 产量的增加在通过缓冲能力提高来增强生物膜的电化学性能方面发挥了作用。本研究首次揭示了缓冲能力对酿造废水处理过程中阳极生物膜分层的调节，深入了解了生物膜结构与其电化学性质的关系。
