用于市政水处理的微滤（MF）和超滤（UF）膜的使用传统上仅限于高质量的地表水源。尽管最近在北美，MF和UF膜系统的接受度和应用度都有了显著提高，但在未进行广泛预处理的情况下，UF和MFM膜通常未应用于平均浊度和总有机碳（TOC）水平分别大于20 NTU和10.0 mg/L的水域。在含有中等至劣质原水的设施中，膜的应用通常仅限于用于抛光处理的沉淀水或过滤水；特别是对于日处理能力超过500万加仑（MGD）的水处理厂。在这种情况下，浸入式膜系统的配置和应用的最新进展为经济地应用超滤膜来大规模处理高浊度和富含有机物的水源提供了机会，而无需使用新的联合处理工艺进行常规预处理。 在这个过程中，真空/吸力驱动的中空纤维膜直接浸入未凝结和絮凝的原水中。这些膜为贾第虫和隐孢子虫等寄生虫以及高浓度的有机和无机固体提供了正屏障，这些固体或悬浮在原水中，或通过混凝和共沉淀形成。这种一体化的混凝/膜工艺无需沉淀和快速重力砂滤，且不会受到高浊度和TOC水平的负面影响。除降低浊度和病原体外，该工艺还可针对天然有机物（NOM）、颜色和TOC降低进行优化，并可与粉末活性炭（PAC）结合使用。这种膜和混凝/吸附预处理工艺的有效结合，大大减少了与新建和改造现有水处理设施相关的经济考虑，以满足日益严格的饮用水质量指南。 因此，浸没式超滤处理设施的预设计和中试研究已经完成，其规模从2-40 MGD不等，直接处理劣质原水。本文所述的这些研究结果表明，浸入式膜，无论是直接使用还是与混凝剂一起使用，都可以应用于低质量水源，同时提供符合当前和拟议监管指南的饮用水，包括消毒剂-消毒副产品（D/DBPR）规则和临时强化地表水处理规则（IESWTR）。介绍了在美国蒙大拿州中美洲和加拿大阿尔伯塔省应用的中试结果和处理后的水质数据。包括5个参考文献、表格、图表。

The use of microfiltration (MF) and ultrafiltration (UF) membranes for municipalwater treatment has traditionally been limited to high quality surface watersources. Despite the recent, significant increase in the acceptance andapplication of both MF and UF membrane systems in North America, UF and MFmembranes have typically not been applied on waters having an average turbidityand total organic carbon (TOC) level greater than 20 NTU and 10.0 mg/L,respectively without extensive pretreatment. The applications of membranes atfacilities with moderate to poor quality raw water have generally been limited toeither settled or filtered water for polishing treatment; particularly for watertreatment plants with capacities greater than 5 million gallons per day (MGD). Inthis context, recent advances in the configuration and application of immersedmembrane systems offers an opportunity to economically apply UF membranes totreat high turbidity, and organic laden water sources on a large scale withoutconventional pretreatment by using a new combined treatment process. With thisprocess, vacuum/suction driven, hollow fiber membranes are directly immersed incoagulated and flocculated raw water. The membranes provide a positive barrier toparasites such as Giardia and Cryptosporidium, as well as high concentrations ofboth organic and inorganic solids, which are either suspended in the raw water ordeveloped by coagulation and co-precipitation. This integratedcoagulation/membrane process eliminates the need for sedimentation and rapidgravity sand filtration and is not negatively impacted by high turbidity and TOClevels. In addition to turbidity and pathogen reduction, the process can also beoptimized for natural organic matter (NOM), color and TOC reduction and can beused in combination with powdered activated carbon (PAC). This efficientcombination of membrane and coagulation/adsorption pretreatment processes hassignificantly reduced the economic considerations associated with construction ofnew and retrofitting existing water treatment facilities to meet increasinglystringent drinking water quality guidelines. As a result, pre-design and pilotstudies have been completed for immersed ultrafiltration treatment facilitiesranging in size from 2-40 MGD treating poor quality raw water directly. Theresults of these studies described in this paper indicate that immersedmembranes, either directly or with a coagulant, can be applied on low qualitywater sources while providing drinking water that meets current and proposedregulatory guidelines including the Disinfectant- Disinfection By-product(D/DBPR) Rule and the Interim Enhanced Surface Water Treatment Rule (IESWTR).Pilot test results and treated water quality data for applications in CentralAmerica, Montana,U.S.A., and Alberta, Canada are presented. Includes 5 references, tables, figures.