氯对细菌与管材间交互作用及附着行为的影响

Effect of chlorine on cell-surface interaction and bacterial adhesion behavior

为探究饮用水中消毒剂对细菌在管材粗糙表面上附着行为的影响机制,探讨了消毒剂条件下细菌在不同类型、不同粗糙程度管材上的附着行为,并借助于基于表面热力学的XDLVO(extended-Derjaguin-Landau-Verwey-Overbeek)理论解析细菌与粗糙表面的交互作用过程.结果表明,投加氯(≤1.0mg/L)明显促进了细菌在管材表面的附着(相较于未投加时扩大4~6倍),且细菌更倾向于在塑料管材表面定殖,增大管材表面粗糙度进一步促进了细菌的附着.基于XDLVO理论解析表明,1.0mg/L氯提高了细菌与管材表面间的酸碱作用项和范德华作用项,进而促进细菌的表面附着行为;而增大管材表面粗糙程度进一步强化了这一交互过程.相较于不锈钢管材,聚氯乙烯和聚乙烯管材促进了其与细菌表面的交互吸引作用能,特别在1.0mg/L氯条件下管材与细菌的相互作用能增加了4~6倍,进而有助于细菌的表面附着聚集.

In this study,disinfectant-shaped bacterial adhesion behaviors on pipes with various materials and roughness were examined to underpin the underlying mechanisms of bacterial surface attachment in drinking water.The interaction between bacteria and rough surfaces was analyzed via XDLVO(extended-Derjaguin-Landau-Verwey-Overbeek)theory based on surface thermodynamics.The results showed that chlorine(≤1.0mg/L)significantly promoted bacterial adhesion on pipe surfaces(with a 4∼6times increment compared to the situation with no chlorine).Besides,bacterial cells tended to colonize the plastic surfaces and increasing surface roughness can further promote surface adhesion.The XDLVO-based theoretical analysis showed that 1.0mg/L chlorine increases the acid-base and van der Waals interaction terms between bacteria and pipe surfaces,which encourages surface adhesion behaviors.Increasing surface roughness further intensifies cell-surface interactions.Compared with stainless steel pipes,polyvinyl chloride and polyethylene surfaces can elevate the interaction energy with bacterial cells,particularly at 1.0mg/L chlorine,which further contributes to bacterial surface attachment and aggregation.