Shaanxi Key Laboratory of Environmental 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, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Shaanxi Key Laboratory of Environmental 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, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
J Hazard Mater. 2021 Feb 5;403:124018. doi: 10.1016/j.jhazmat.2020.124018. Epub 2020 Sep 17.
In drinking water distribution pipeline systems, the tap water quality is regulated by several biotic and abiotic factors, which can threaten the health of consumers. Stagnation is inevitable in the water distribution pipeline however, the combined effects of seasonal changes and stagnation on tap water quality are not well understood. Here, we investigated the seasonal variations in the chemical and biological quality of water after overnight stagnation for a period of one year. The results showed that the tap water quality deteriorated after overnight stagnation, with up to a 2.7-fold increase in the total iron concentrations. The total bacterial cell concentrations increased by 59-231% after overnight stagnation. The total cell and cell-bound adenosine triphosphate (ATP) of the stagnant water samples peaked in summer. In addition, Biolog analysis showed that the metabolic activities of microbes were higher in spring. The bacterial community based on Illumina Miseq DNA sequence analysis found that Proteobacteria dominated the drinking water bacterial community. The bacterial community structure varied significantly among different seasons, where the diversity and richness of the community were much higher in spring. Structural equation modeling (SEM) was constructed to determine the correlations between bacterial metabolic functions and the community structure. The redundancy analysis (RDA) indicated that the residual chlorine played a critical role in the construction of the bacterial community. Altogether, the overall findings from the present work provide novel insights into how the quality of tap water quality impacted by the seasonal changes and overnight stagnation.
在饮用水分配管道系统中，自来水水质受到多种生物和非生物因素的调节，这些因素可能会威胁到消费者的健康。然而，在配水管道中不可避免会出现停滞现象，季节性变化和停滞对自来水水质的综合影响尚不清楚。在这里，我们研究了经过一夜停滞期后一年内自来水水质的化学和生物季节性变化。结果表明，自来水水质在隔夜停滞后恶化，总铁浓度最高增加了 2.7 倍。总细菌细胞浓度在隔夜停滞后增加了 59-231%。停滞水样的总细胞和细胞结合的三磷酸腺苷（ATP）在夏季达到峰值。此外，Biolog 分析表明，春季微生物的代谢活性更高。基于 Illumina Miseq DNA 序列分析的细菌群落发现，变形菌门在饮用水细菌群落中占主导地位。细菌群落结构在不同季节之间存在显著差异，其中春季的群落多样性和丰富度要高得多。结构方程模型（SEM）用于确定细菌代谢功能与群落结构之间的相关性。冗余分析（RDA）表明，余氯在细菌群落的构建中起着关键作用。总之，本研究的总体结果提供了关于季节性变化和隔夜停滞如何影响自来水水质的新见解。
