College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore, 637141, Singapore.
Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan, 430065, China.
J Environ Manage. 2023 Jul 15;338:117770. doi: 10.1016/j.jenvman.2023.117770. Epub 2023 Mar 23.
This work reported the development, performance and microbial community of microalgal-bacterial biofilms cultivated in a continuous-flow photoreactor for municipal wastewater treatment under various conditions. Results showed that microalgal-bacterial biofilms were successfully developed at a HRT of 9 h without external aeration, with a biofilm concentration of around 4690 mg/L being achieved in the steady-state. It was found that further increase of HRT to 12 h did not improve the overall accumulation of biofilm, whereas the growth of microalgae in biofilms was faster than bacteria in the initial stage, indicated by an increased chlorophyll-a&b content in biofilms. After which, the chlorophyll-a&b content in biofilms gradually stabilized at the level comparable with the seed, suggesting that there was a balanced distribution of microalgae and bacteria in biofilms. About 90% of TOC, 71.4% of total nitrogen and 72.6% of phosphorus were removed by microalgal-bacterial biofilms mainly through assimilation in the steady-state photoreactor run at the HRT of 12 h with external aeration. The community analysis further revealed that Cyanobacteria and Chloroflexi were the main components, while Chlorophyta appeared to be the dominant eukaryotic algal community in biofilms. This study could offer new insights into the development of microalgal-bacterial biofilms in a continuous-flow photoreactor for sustainable low-carbon municipal wastewater treatment.
本研究报道了在不同条件下，连续流光反应器中用于城市污水处理的微藻-细菌生物膜的开发、性能和微生物群落。结果表明，在无外部曝气、HRT 为 9 h 的条件下成功开发了微藻-细菌生物膜，在稳定状态下生物膜浓度达到约 4690 mg/L。进一步将 HRT 增加到 12 h 并没有提高生物膜的整体积累，而生物膜中藻类的生长速度比细菌快，这可以通过生物膜中叶绿素-a&b 含量的增加来证明。之后，生物膜中叶绿素-a&b 的含量逐渐稳定在与种子相当的水平，表明生物膜中微藻和细菌之间存在平衡的分布。在 HRT 为 12 h 并进行外部曝气的稳定状态光反应器中，微藻-细菌生物膜主要通过同化作用去除了约 90%的 TOC、71.4%的总氮和 72.6%的磷。群落分析进一步表明，蓝藻和绿弯菌门是主要组成部分，而绿藻门似乎是生物膜中优势的真核藻类群落。本研究可为连续流光反应器中用于可持续低碳城市污水处理的微藻-细菌生物膜的开发提供新的见解。
