TZW: DVGW-Technologiezentrum Wasser, Karlsruher Straße 84, Karlsruhe 76139, Germany.
Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, Garching 85748, Germany.
Water Res. 2024 Dec 1;267:122429. doi: 10.1016/j.watres.2024.122429. Epub 2024 Sep 10.
In this study, we evaluated the ability of various pilot-scale treatment train combinations to meet the microbial requirements of the new European non-potable water reuse regulation 2020/741. The study utilized non-disinfected secondary effluent from the wastewater treatment plant in Schweinfurt, Germany, as feedwater for two pilot-scale treatment trains. The first, a reference treatment train (Train A), consisted of filtration and UV disinfection as specified for reclaimed water class A in the EU regulation. The second, an advanced treatment train (Train B), included ceramic ultrafiltration (UF), ozonation, biological activated carbon filtration (BAC), and final UV disinfection. Based on a Monte Carlo simulation for Train A, the EU requirements for pathogen removal were not met when an average UV dose of 400-600 J m was applied. This shortcoming was likely due to a moderate transmittance range (50-65 %), resulting in decreased UV fluence. These findings suggest that operational conditions for disinfection should be more clearly specified to ensure consistent pathogen inactivation both during validation and regular operation. In contrast, treatment train B successfully met the requirements of the EU regulations by reducing pathogens to below the detection limit. The UF membrane demonstrated a positive effect on the overall log reduction values (LRVs) throughout the water reclamation system. It also enhanced the efficiency of downstream processes, such as ozonation and UV disinfection, by lowering total suspended solids and turbidity. However, even without the UF membrane, treatment train B was still able to meet the pathogenic EU requirements for non-potable reuse applications. Furthermore, the study observed that the inclusion of biologically activated carbon (BAC) filtration requires a final disinfection step (e.g., UV disinfection) to prevent the potential occurrence of heterotrophic bacteria that proliferate in the BAC filter. For process validation it is recommended to use at least two different virus surrogates (MS2 and PhiX174), rather than just one or total coliphage as required in the EU regulation.
在这项研究中，我们评估了各种中试处理组合的能力，以满足新的 2020/741 年欧洲非饮用水再利用法规对微生物的要求。该研究利用德国施魏因富特污水处理厂未经消毒的二级出水作为两个中试处理系统的进水。第一个是参考处理系统（列车 A），包括过滤和紫外线消毒，符合欧盟法规中对再生水 A 类的规定。第二个是先进的处理系统（列车 B），包括陶瓷超滤（UF）、臭氧氧化、生物活性炭过滤（BAC）和最终的紫外线消毒。基于列车 A 的蒙特卡罗模拟，当应用平均紫外线剂量为 400-600 J m 时，病原体去除的欧盟要求未得到满足。这一缺陷可能是由于中等透射率范围（50-65%）导致紫外线强度降低。这些发现表明，消毒的操作条件应更明确地规定，以确保在验证和常规运行期间都能持续灭活病原体。相比之下，处理系统 B 通过将病原体降低到检测限以下，成功地满足了欧盟法规的要求。UF 膜在整个水回收系统中对整体对数减少值（LRV）产生了积极影响。它还通过降低总悬浮固体和浊度，提高了下游过程（如臭氧氧化和紫外线消毒）的效率。然而，即使没有 UF 膜，处理系统 B 仍然能够满足非饮用水再利用应用的欧盟病原体要求。此外，研究还观察到，生物活性炭（BAC）过滤的加入需要最后的消毒步骤（如紫外线消毒），以防止在 BAC 过滤器中繁殖的异养细菌的潜在发生。对于工艺验证，建议使用至少两种不同的病毒替代物（MS2 和 PhiX174），而不是像欧盟法规中要求的那样只使用一种或总大肠菌噬菌体。
