State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China.
Research group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerp 2020, Belgium.
Sci Rep. 2017 Apr 3;7:45609. doi: 10.1038/srep45609.
Sustainable wastewater treatment has been attracting increasing attentions over the past decades. However, the production of nitrous oxide (NO), a potent GHG, from the energy-efficient granule-based autotrophic nitrogen removal is largely unknown. This study applied a previously established NO model, which incorporated two NO production pathways by ammonia-oxidizing bacteria (AOB) (AOB denitrification and the hydroxylamine (NHOH) oxidation). The two-pathway model was used to describe NO production from a granule-based partial nitritation (PN) reactor and provide insights into the NO distribution inside granules. The model was evaluated by comparing simulation results with NO monitoring profiles as well as isotopic measurement data from the PN reactor. The model demonstrated its good predictive ability against NO dynamics and provided useful information about the shift of NO production pathways inside granules for the first time. The simulation results indicated that the increase of oxygen concentration and granule size would significantly enhance NO production. The results further revealed a linear relationship between NO production and ammonia oxidation rate (AOR) (R = 0.99) under the conditions of varying oxygen levels and granule diameters, suggesting that bulk oxygen and granule size may exert an indirect effect on NO production by causing a change in AOR.
在过去几十年中，可持续的废水处理受到了越来越多的关注。然而，从节能的颗粒基自养脱氮中产生氧化亚氮（N2O），一种强效温室气体，这在很大程度上是未知的。本研究应用了先前建立的包含氨氧化菌（AOB）两种 NO 生成途径（AOB 反硝化和羟胺（NHOH）氧化）的 NO 模型。该双途径模型用于描述基于颗粒的部分硝化（PN）反应器中的 NO 生成，并深入了解颗粒内部的 NO 分布。通过将模拟结果与 NO 监测曲线以及 PN 反应器的同位素测量数据进行比较，对模型进行了评估。该模型对 NO 动力学具有良好的预测能力，并首次提供了有关颗粒内部 NO 生成途径转变的有用信息。模拟结果表明，氧气浓度和颗粒尺寸的增加会显著增强 NO 的生成。结果进一步表明，在氧气水平和颗粒直径变化的条件下，NO 生成与氨氧化速率（AOR）之间存在线性关系（R = 0.99），这表明，在一定条件下，主体氧气和颗粒尺寸可能通过改变 AOR 对 NO 生成产生间接影响。
