Vandcenter Syd A/S, Vandværksvej 7, Odense 5000, Denmark; Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads 228A, Kgs. Lyngby 2800, Denmark.
Vandcenter Syd A/S, Vandværksvej 7, Odense 5000, Denmark.
Sci Total Environ. 2024 Jan 15;908:168030. doi: 10.1016/j.scitotenv.2023.168030. Epub 2023 Oct 27.
The upcoming change of legislation in some European countries where wastewater treatment facilities will start to be taxed based on direct greenhouse gas (GHG) emissions will force water utilities to take a closer look at nitrous oxide (NO) production. In this study, we report for the first time NO emissions from two full-scale size membrane aerated biofilm reactors (MABR) (R1, R2) from two different manufacturers treating municipal wastewater. NO was monitored continuously for 12 months in both the MABR exhaust gas and liquid phase. Multivariate analysis was used to assess process performance. Results show that emission factors (EF) for both R1 and R2 (0.88 ± 1.28 and 0.82 ± 0.86 %) were very similar to each other and below the standard value from the Intergovernmental Panel on Climate Change (IPCC) 2019 (1.6 %). More specifically, NO was predominantly emitted in the MABR exhaust gas (NTR) and was strongly correlated to the ammonia/um load (NH). Nevertheless, the implemented Oxidation Reduction Potential (ORP) control strategy increased the bulk contribution (NTR), impacting the overall EF. A thorough analysis of dynamic data reveals that the changes in the external aeration (EA)/loading rate patterns suggested by ORP control substantially impacted NO mass transfer and biological production processes. It also suggests that NTR is mainly caused by ammonia-oxidizing organisms (AOO) activity, while ordinary heterotrophic organisms (OHO) are responsible for NTR. Different methods for calculating EF were compared, and results showed EF would range from 0.6 to 5.5 depending on the assumptions made. Based on existing literature, a strong correlation between EF and nitrogen loading rate (R = 0.73) was found for different technologies. Overall, an average EF of 0.86 % NO-N per N load was found with a nitrogen loading rate >200 g N m d, which supports the hypothesis that MABR technology can achieve intensified biological nutrient removal without increasing NO emissions.
即将在一些欧洲国家出台的法规变更要求污水处理厂开始根据直接温室气体 (GHG) 排放量缴税，这将迫使水务公司更密切地关注一氧化二氮 (NO) 的产生。在这项研究中，我们首次报告了来自两家不同制造商的两个全尺寸膜曝气生物膜反应器 (MABR) (R1、R2) 处理城市污水时的 NO 排放情况。在 MABR 废气和液相中连续监测了 12 个月的 NO。采用多元分析来评估工艺性能。结果表明，R1 和 R2 的排放因子 (EF) (0.88 ± 1.28 和 0.82 ± 0.86%) 非常相似，均低于政府间气候变化专门委员会 (IPCC) 2019 年的标准值 (1.6%)。更具体地说，NO 主要在 MABR 废气 (NTR) 中排放，与氨/UM 负荷 (NH) 呈强相关。然而，实施的氧化还原电位 (ORP) 控制策略增加了主体贡献 (NTR)，从而影响了整体 EF。对动态数据的深入分析表明，ORP 控制建议的外部曝气 (EA)/加载率模式的变化对 NO 质量传递和生物生产过程产生了重大影响。它还表明，NTR 主要是由氨氧化生物 (AOO) 活性引起的，而普通异养生物 (OHO) 则负责 NTR。比较了不同的 EF 计算方法，结果表明 EF 范围在 0.6 到 5.5 之间，具体取决于假设。根据现有文献，发现不同技术的 EF 与氮负荷率 (R)之间存在很强的相关性 (R=0.73)。总体而言，在氮负荷率 >200 g N m d 时，每氮负荷 0.86% 的平均 EF 发现为 0.86% 的 NO-N，这支持了 MABR 技术可以在不增加 NO 排放的情况下实现强化生物营养去除的假设。
