Zhang Xiaohan, Niu Zhiguang, Chen Mingyu, Ma Yongzheng, Wang Yue, Sun Yueling, Zhang Ying
School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
Special Pollutant Administration Center of Hefei Municipal, Hefei 230601, China.
Water Res. 2025 Oct 1;285:124055. doi: 10.1016/j.watres.2025.124055. Epub 2025 Jun 19.
The water supply system is a crucial infrastructure related to the people's livelihood. To enhance the performance of pipelines, additives are commonly added to the plastic pipes. Among these, phthalate esters (PAEs), a type of emerging contaminants, have been proven to be released from plastic pipes to water. In this study, we investigated the occurrence of PAEs in drinking water supply systems, isolated PAE-degrading bacteria and explored their characteristics. Firstly, a total of six PAEs were detected throughout the process from raw water to tap water, and the concentrations of ΣPAEs in tap water at three sampling sites were all higher than those in the finished water. Secondly, using PAEs as the sole carbon source, four strains of PAE-degrading bacteria were isolated from the simulated pipeline biofilm. Within 12 h, the degradation rates of these four strains towards ΣPAEs (initial concentration: 1 mg/L) were 34.83 % - 56.54 %. Thirdly, considering the presence of multiple carbon sources, residual chlorine, and other bacteria, the behavior of the isolated PAE-degrading bacteria in the actual pipeline environment was examined. It showed that PAE-degrading bacteria preferentially used other carbon sources in tap water rather than PAEs, and the residual chlorine inhibited the bacteria's ability to degrade PAEs. Moreover, despite the presence of other bacteria from the biofilm, the PAE-degrading bacteria still became the dominant bacteria. Consequently, this study demonstrated the feasibility of PAE degradation by bacteria isolated from the pipeline biofilm, which was helpful for understanding the biochemical degradation process of PAEs in drinking water supply systems.
供水系统是一项关乎民生的关键基础设施。为提高管道性能，通常会向塑料管道中添加添加剂。其中，邻苯二甲酸酯（PAEs）作为一类新兴污染物，已被证实会从塑料管道释放到水中。在本研究中，我们调查了饮用水供应系统中PAEs的存在情况，分离出PAE降解菌并探究了它们的特性。首先，从原水到自来水的整个过程中共检测到六种PAEs，三个采样点的自来水中ΣPAEs浓度均高于出厂水。其次，以PAEs作为唯一碳源，从模拟管道生物膜中分离出四株PAE降解菌。在12小时内，这四株菌对ΣPAEs（初始浓度：1mg/L）的降解率为34.83% - 56.54%。第三，考虑到多种碳源、余氯和其他细菌的存在，考察了分离出的PAE降解菌在实际管道环境中的行为。结果表明，PAE降解菌优先利用自来水中的其他碳源而非PAEs，余氯抑制了细菌降解PAEs的能力。此外，尽管生物膜中存在其他细菌，PAE降解菌仍成为优势菌。因此，本研究证明了从管道生物膜中分离出的细菌降解PAE的可行性，这有助于了解饮用水供应系统中PAEs的生化降解过程。
