Mathematical Modeling of the Dynamic Effect of Denitrifying Glycogen-accumulating Organisms on Nitrous Oxide Production during Denitrifying Phosphorus Removal
Mathematical Modeling of the Dynamic Effect of Denitrifying Glycogen-accumulating Organisms on Nitrous Oxide Production during Denitrifying Phosphorus Removal
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DOI：
10.1016/j.cej.2022.139802
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发表时间：
2022-10
影响因子：
15.1
通讯作者：
Shuqi Ren;Yingrui Liu;Yanying He;Tingting Zhu;Xueming Chen;Yiwen Liu
中科院分区：
文献类型：
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作者：
Shuqi Ren;Yingrui Liu;Yanying He;Tingting Zhu;Xueming Chen;Yiwen Liu
反硝化除磷(DPR)产生的大量中间体氧化亚氮(N2O)增加了废水处理的碳足迹。然而，对于反硝化聚磷菌(DPAO)和反硝化聚磷菌(DGAO)在反硝化聚磷菌(DPAO)和反硝化糖原积累菌(DGAO)在DPR过程中对N2O产生的相互关系缺乏详细的了解。在这项工作中，首次建立了描述DPAO和DGAO共存的DPR系统中N2O动态产生的数学模型。该模型考虑了硝酸盐、亚硝酸盐、一氧化氮和N2O随后的四步反硝化作用。通过与DPR三篇独立报道的实验数据的比较，充分验证了模型的有效性，这些实验数据令人满意地描述了N2O产生、氮氧化物还原、磷酸盐释放和吸收以及胞内聚合物周转的动力学过程。验证后的模型可以阐明N2O产生的来源和途径。随后，通过模型模拟研究了各关键操作条件对总N2O产生量、DPAO和DGAOS竞争以及营养盐去除效率的综合影响。模拟结果表明，在厌氧阶段，DGAOS的聚羟基烷酸储存率高于DPAOS；在缺氧阶段，DGAOS对硝酸盐电子受体的选择性较高。在低COD(<；150 mg/L)和高硝酸盐(>；35 mg/L)条件下，DGAO对DPAO的生长竞争占主导地位，导致DGAO对糖原的缺氧储存成为产生N2O的主要途径。此外，与单一的DGAOS或DPAOS系统相比，该系统中N2O的产生和生成途径都具有更大的变异性，进一步表明了该模型的必要性。
The large amount of intermediate nitrous oxide (N2O) production from denitrifying phosphorus removal (DPR) increases the carbon footprint of wastewater treatment. However, there is a lack of detailed understanding of the interrelationships between denitrifying polyphosphate-accumulating organisms (DPAOs) and denitrifying glycogen-accumulating organisms (DGAOs) on N2O production during DPR. In this work, a mathematical model was developed for the first time to describe dynamic N2O production in the DPR system coexisting DPAOs and DGAOs. The model took into account a four-step subsequent denitrification of nitrate, nitrite, nitric oxide, and N2O. The validity of model was fully tested by comparing simulation studies with experimental data from three independent reports on DPR, which satisfactorily described the dynamics of N2O production, nitrogen oxide reduction, phosphate release and uptake, and intracellular polymers turnover. The validated model could clarify the source and pathways of N2O production. Subsequently, the combined effects of key operational conditions on the overall N2O production, DPAOs and DGAOs competition, and nutrients removal efficiency were investigated by model simulation. Simulation results showed higher polyhydroxyalkanoate storage rate of DGAOs than that of DPAOs during anaerobic stage and the preference of DGAOs for nitrate electron acceptor during anoxic stage. DGAOs dominated the growth competition over DPAOs at low COD (<150 mg/L) and high nitrate (>35 mg/l) conditions, leading to the anoxic storage of glycogen by DGAOs as the main pathway of N2O production. In addition, both N2O production and generation pathways in the system possessed greater variability compared to single DGAOs or DPAOs system, further indicating the necessity of this model.