The use of reverse osmosis (RO) membranes has been expanding not only to medical applications but also to water supply and reclaimed water applications due to its strong ability to remove a wide range of contaminants. Many researchers reported RO performance as a barrier against waterborne viruses; however, there are limited reports on its ability to remove bacteria from water. This investigation evaluated the removal performances of several spiral-wound RO modules and a hollow fiber ultrafiltration (UF) module in two different ways: dosing tests in batch-wise mode operation and in continuous-mode operation. The dosing tests of Escherichia coli using RO modules confirmed that E. coli could leak from the feed-side into the permeate. The log removal values (LRVs) (4.21- to >7.44-log₁₀) by the RO modules from different production lots were found to vary greatly. In continuous-mode operation of the RO module, the LRVs for indigenous heterotrophic bacteria decreased over the operation period. These results clearly illustrate that bacteria, which originate on the feed-side, can leak into the permeate-side and then begin to proliferate in the permeate. On the other hand, using a UF module, E. coli was not detected in the permeate regardless of the operation mode.

由于反渗透膜具有很强的去除多种污染物的能力，因此其用途不仅已扩展到医疗应用，而且已扩展到供水和再生水应用。许多研究人员报告说，反渗透性能是抵抗水传播病毒的障碍。然而，关于其从水中去除细菌的能力的报道很少。这项研究以两种不同的方式评估了几种螺旋缠绕式RO模块和中空纤维超滤（UF）模块的去除性能：分批模式操作和连续模式操作中的定量测试。使用反渗透模块对大肠埃希氏菌进行剂量测试，证实大肠埃希菌可能从进料侧泄漏到渗透液中。对数清除值（LRV）（4.21至> 7.44 log₁₀）来自不同生产批次的反渗透模块发现差异很大。在反渗透模块的连续模式操作中，本地异养细菌的LRV在操作期间有所减少。这些结果清楚地说明，起源于进料侧的细菌可以泄漏到渗透侧，然后开始在渗透侧扩散。另一方面，使用UF模块，无论操作模式如何，都无法在渗透液中检测到大肠杆菌。