户内热水供水管道特殊水力工况对微生物生长的影响

Effect of special hydraulic regimes on growth of microorganisms in hot water premise plumbing

关键词:  户内热水供水管道  水力工况  微生物群落结构  潜在致病菌属

Key words:  hot water premise plumbing  hydraulic regimes  microbial community  potential pathogens genus

摘要:

户内热水供水管道高温环境和户内用水模式的差异使其具有特殊的管道微生物群落特征,从而影响用户用水安全性。为此,搭建非循环式户内热水供水管道模拟试验平台,研究户内热水供水系统高变流（HIG）、低变流（LOW）、恒定流量（SS）和滞留（R）4种特殊水力工况对微生物生长的影响。试验平台运行91 d后采集相应的生物膜样和管网水样,分析样品中的细菌数量,通过16S rRNA基因测序方法分析样品的微生物群落结构和潜在致病菌属的存在水平,评估样品的潜在致病风险。结果表明:R工况水样和膜样的微生物数量最高,两种连续变化流量工况HIG和LOW的微生物数量较低,活菌更倾向于在生物膜上定殖,膜样中的潜在致病菌属数量和相对丰度更高；连续变化流量工况膜样中的3种典型潜在致病菌属,即假单胞菌属、军团菌属和分枝杆菌属的相对丰度也更高,具有更高的潜在致病风险。

Abstract:

High-temperature environments and variations in hot water premise plumbing create unique microbial community characteristics that impact water safety. This study utilized a simulation platform for non-circulating hot water premise plumbing to investigate microbial growth under the effects of four specific hydraulic regimes: high variable flow (HIG), low variable flow (LOW), steady state (SS), and retention (R) conditions. After 91 days of operation, biofilm and water samples were collected from the simulation platform. The bacterial counts in the samples were measuerd, and the microbial community structure and the presence of potential pathogens genus were evaluated using 16S rRNA gene sequencing. The results showed that the R condition led to the highest microbial counts in both water and biofilm samples, while the continuously varying flow conditions, LOW and HIG, showed lower counts. Live bacteria demonstrated a propensity to colonize biofilms, exhibiting increased numbers and relative abundances of potentially pathogenic genera in the membrane samples. In addition, biofilms under varying flow conditions exhibited higher relative abundances of three typical potentially pathogenic genera, Pseudomonas spp., Legionella spp., and Mycobacterium spp., indicating a greater potential pathogenic risk.