UCIBIO-REQUIMTE, Department of Chemistry, Faculty of Sciences and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
Sci Total Environ. 2022 May 15;821:153492. doi: 10.1016/j.scitotenv.2022.153492. Epub 2022 Jan 30.
In next-generation water resource recovery facilities (WRRFs), it is becoming increasingly important to save energy costs and promote resource recovery of valuable products. One way of reducing the substantial aeration energy costs at WRRFs is to employ shortcut N removal, while polyhydroxyalkanoate (PHA) production and recovery as bioplastic is a promising means of recovering a valuable product from biosolids. Both objectives can be achieved simultaneously through the Short-Cut Enhanced Phosphorus and PHA Recovery (SCEPPHAR) process. However, current mathematical models have not previously been employed to describe the behavior of such a process, which limits engineering design and optimisation of process operation. This work focusses on extending the ASM3 model towards the description of short-cut nitrogen removal and simultaneous PHA recovery in a sidestream treatment process. The calibrated and validated model described very well the nitritation process coupled with the aerobic feast/anoxic famine process for the selection of PHA producing organisms at a pilot-scale facility operated in Carbonera, Italy, where the normalised root mean squared error (NRMSE) was consistently <20%. Furthermore, the model applied to the PHA selection stage could effectively describe the PHA accumulation stage without recalibration. A simulation study was performed using the modified ASM3 model to assess the relative benefits of the SCEPPHAR process strategy as compared to the fully aerobic selection process for mixed culture PHA production. While the level of PHA production was found to be 34% lower with SCEPPHAR, a 43% savings in volatile fatty acids (VFAs) demand, a 15% decrease in Total suspended solids (TSS) production and a 28% decrease in oxygen demand were also achievable, which could lead to savings in operational costs. This study facilitates the design and optimisation of WRRFs that integrate short-cut N removal with PHA production, saving aeration energy costs while achieving resource recovery.
在新一代水资源回收设施 (WRRF) 中，节约能源成本和促进有价值产品的资源回收变得越来越重要。降低 WRRF 大量曝气能源成本的一种方法是采用短程脱氮，而聚羟基烷酸酯 (PHA) 的生产和回收作为生物塑料是从生物固体中回收有价值产品的一种有前途的方法。这两个目标可以通过短程增强磷和 PHA 回收 (SCEPPHAR) 工艺同时实现。然而，目前的数学模型以前没有被用来描述这样一个过程的行为，这限制了工程设计和过程操作的优化。这项工作的重点是扩展 ASM3 模型，以描述侧流处理过程中的短程脱氮和同时 PHA 回收。该模型经过校准和验证，很好地描述了硝化过程，以及在意大利 Carbonera 运营的中试设施中，通过好氧丰食/缺氧饥饿过程选择 PHA 产生菌的过程，归一化均方根误差 (NRMSE) 始终保持在 <20%。此外，该模型应用于 PHA 选择阶段，可以在无需重新校准的情况下有效地描述 PHA 积累阶段。使用修改后的 ASM3 模型进行了模拟研究，以评估与完全好氧选择工艺相比，SCEPPHAR 工艺策略的相对优势，用于混合培养 PHA 生产。虽然 SCEPPHAR 的 PHA 产量低 34%，但挥发性脂肪酸 (VFAs) 需求减少 43%，总悬浮固体 (TSS) 产量减少 15%，耗氧量减少 28%，这可能导致运营成本的节约。这项研究促进了将短程脱氮与 PHA 生产相结合的 WRRF 的设计和优化，节省了曝气能源成本，同时实现了资源回收。
