Due to rapid growth in the potable reuse industry, there is a need to better characterize the associated pathogen risks and degree of attenuation achieved by various treatment trains. It is also important to understand how emerging treatment frameworks compare to the historical practice of de facto reuse. As such, the goals of this study were to (1) evaluate the equivalency of indirect potable reuse (IPR) and direct potable reuse (DPR) systems; (2) compare alternative treatment trains; and (3) identify the design components and operational conditions that are most critical to minimizing public health risks. To this end, we developed a static quantitative microbial risk assessment (QMRA) for Cryptosporidium, norovirus, adenovirus, and Salmonella. Treatment process performance (including failure scenarios) and resultant public health risks were estimated using a Stella 10.1 system dynamics model. The combined annual risk of infection was lower in DPR systems with no surface water influence [median risk = 1.1 × 10⁻⁸ for ozone-based DPR and 3.9 × 10⁻⁶ for DPR with reverse osmosis (RO)] compared with IPR systems or DPR with raw water augmentation (median risk = 9.0 × 10⁻⁴ to 3.8 × 10⁻³). Although de facto reuse, planned IPR, and DPR with raw water augmentation exceeded the common 10⁻⁴ annual risk benchmark, the risks were generally dominated by the pathogen concentrations in the upstream surface water, thereby highlighting the importance of source water characterization in all drinking water systems. Moreover, the risk calculation for each system was often dominated by a particular pathogen (e.g., adenovirus with a maximum risk of 3.7 × 10⁻² for RO-based DPR during a compound failure). Sensitivity analyses demonstrated that storage time and temperature were important for de facto reuse and during compound failures and that risks generally decreased with greater recycled water contributions (RWC) due to the robustness of advanced treatment and/or attenuation in the environmental buffer.

由于便携式再利用工业的快速增长，需要更好地表征相关的病原体风险和各种处理方法所实现的减毒程度。同样重要的是要了解新兴的治疗框架如何与事实上的重用的历史实践进行比较。因此，本研究的目标是（1）评估间接饮用重复使用（IPR）和直接饮用重复使用（DPR）系统的等效性；（2）比较替代治疗方案；（3）确定对最小化公共健康风险最关键的设计组成部分和操作条件。为此，我们开发了针对隐孢子虫，诺如病毒，腺病毒和沙门氏菌的静态定量微生物风险评估（QMRA）。使用Stella 10.1系统动力学模型评估了处理过程的性能（包括故障场景）和由此产生的公共健康风险。与IPR系统相比，在没有地表水影响的DPR系统中，合并的年度感染风险较低[臭氧基DPR的中位风险= 1.1×10 ^-8，反渗透（RO）的DPR中位风险= 3.9×10 ^-6 ]或增加原水的DPR（中位风险= 9.0×10 ^-4至3.8×10 ^-3）。尽管事实上的再利用，计划的IPR和原水增加的DPR超过了常见的10 ^-4在年度风险基准中，风险通常由上游地表水中的病原体浓度决定，从而突出了在所有饮用水系统中表征原水的重要性。此外，每个系统的风险计算通常由特定的病原体主导（例如，在复合失效期间，基于RO的DPR的最大风险为3.7×10 ^-2的腺病毒）。敏感性分析表明，存储时间和温度对于事实上的再利用和复合物故障非常重要，并且由于先进处理的坚固性和/或环境缓冲液的衰减，通常随着回收水贡献量（RWC）的增加，风险通常会降低。