KWR Watercycle Research Institute, Groningenhaven 7, 3433PE, Nieuwegein, the Netherlands.
Oasen N.V., Nieuwe Gouwe O.Z. 3, 2801 SB, Gouda, the Netherlands.
Water Res. 2019 Jun 15;157:55-63. doi: 10.1016/j.watres.2019.03.037. Epub 2019 Mar 21.
Treatment processes, such as membrane filtration with reverse osmosis (RO), are used to produce drinking water with a high degree of biostability. To our knowledge, the influence of RO water on biofilm formation and growth of L. pneumophila has not yet been investigated. Therefore, this study aimed (i) to determine the Legionella growth potential of (remineralised) RO-water produced by a pilot plant and to compare this to conventional treated groundwater, and (ii) to determine if different pipe materials, in contact with remineralised RO-water, can cause growth of L. pneumophila. The Legionella growth potential of water was determined with the boiler biofilm monitor (BBM) that mimics the flow of water in a premise plumbing system. The Legionella growth potential of materials in contact with remineralised RO-water was determined by using the biomass production potential (BPP)-test. ATP concentrations in the biofilm on the glass rings from the BBM fed with (remineralised) RO water fluctuated around 100 pg ATP cm. In contrast, BBMs fed with conventionally treated water resulted in ten-fold higher ATP concentrations in the biofilm. Moreover, conventionally treated water had a Legionella growth potential that was 1000-fold higher than that of (remineralised) RO-water. Furthermore, glass, copper and PVC-C had the lowest biofilm concentrations and Legionella growth potential in the BPP-test, followed by PE-Xb, PE-Xc and PE-100. The highest biofilm concentration and Legionella growth potential were with PVC-P. Hence, our study demonstrated that remineralised RO-water did not enhance growth of L. pneumophila in the BBM that mimics the premises plumbing system. However, when PE or PVC-P materials are used growth of L. pneumophila can still occur in the premises plumbing system despite the high quality of the supplied remineralised RO-water.
处理工艺，如反渗透（RO）膜过滤，用于生产具有高度生物稳定性的饮用水。据我们所知，RO 水对嗜肺军团菌生物膜形成和生长的影响尚未被研究过。因此，本研究旨在：（i）确定由中试工厂生产的（再矿化）RO 水的军团菌生长潜力，并将其与常规处理的地下水进行比较；（ii）确定与再矿化 RO 水接触的不同管材是否会导致嗜肺军团菌的生长。采用模拟管网系统水流的锅炉生物膜监测仪（BBM）来确定水中的军团菌生长潜力。通过使用生物量产生潜力（BPP）试验来确定与再矿化 RO 水接触的材料的军团菌生长潜力。从 BBM 中用（再矿化）RO 水喂养的玻璃环上的生物膜中的 ATP 浓度在 100 pg ATP cm 左右波动。相比之下，用常规处理水喂养的 BBM 导致生物膜中的 ATP 浓度增加了十倍。此外，常规处理水的军团菌生长潜力比（再矿化）RO 水高 1000 倍。此外，在 BPP 试验中，玻璃、铜和 PVC-C 的生物膜浓度和军团菌生长潜力最低，其次是 PE-Xb、PE-Xc 和 PE-100。生物膜浓度和军团菌生长潜力最高的是 PVC-P。因此，我们的研究表明，再矿化 RO 水并没有增强模拟管网系统的 BBM 中嗜肺军团菌的生长。然而，当使用 PE 或 PVC-P 材料时，尽管供应的再矿化 RO 水质量很高，但嗜肺军团菌仍可能在管网系统中生长。
