Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Sci Total Environ. 2023 Nov 10;898:165473. doi: 10.1016/j.scitotenv.2023.165473. Epub 2023 Jul 14.
Endogenous pollution due to long periods of hypolimnetic anoxia in stratified reservoirs has become a worldwide concern, which can threaten metabolic activity, biodiversity, water quality security, and ultimately human health. In the present study, an artificial mixing system applied in a drinking water reservoir was developed to reduce pollutants, and the biological mechanism involved was explored. After approximately 44 days of system operation, the reservoir content was completely mixed resulting in the disappearance of anoxic layers. Furthermore, the metabolic activity estimated by the Biolog-ECO microplate technique and biodiversity was enhanced. 16S rRNA gene sequencing indicated a great variability on the composition of bacterial communities. Co-occurrence network analysis showed that interactions among bacteria were significantly affected by the proposed mixing system. Bacteria exhibited a more mutualistic state and >10 keystone genera were identified. Pollutants, including nitrogen, phosphorus, organic matter, iron, and manganese decreased by 30.63-80.15 %. Redundancy discriminant analysis revealed that environmental factors, especially the temperature and dissolved oxygen, were crucial drivers of the bacterial community structure. Furthermore, Spearman's correlation analysis between predominant genera and pollutants suggested that core genus played a vital role in pollutant reduction. Overall, our findings highlight the importance and provide insights on the artificial mixing systems' microbial mechanisms of reducing pollutants in drinking water reservoirs.
由于分层水库底层缺氧时间过长而导致的内源污染已成为一个全球性问题，这可能会威胁到代谢活动、生物多样性、水质安全，并最终影响人类健康。在本研究中，开发了一种应用于饮用水库的人工混合系统来减少污染物，并探讨了其中涉及的生物学机制。在系统运行约 44 天后，水库中的水完全混合，缺氧层消失。此外，通过 Biolog-ECO 微平板技术和生物多样性评估，发现代谢活性和生物多样性得到了增强。16S rRNA 基因测序结果表明，细菌群落的组成具有很大的变异性。共生网络分析表明，细菌之间的相互作用受到所提出的混合系统的显著影响。细菌呈现出更互利的状态，鉴定出了>10 个关键属。氮、磷、有机物、铁和锰等污染物的去除率为 30.63-80.15%。冗余判别分析表明，环境因素，尤其是温度和溶解氧，是细菌群落结构的关键驱动因素。此外，优势属与污染物之间的 Spearman 相关性分析表明，核心属在污染物去除中起着至关重要的作用。总之，本研究结果强调了人工混合系统在减少饮用水库中污染物方面的重要性和微生物机制。
