硝化细菌
硝基螺
硝化作用
硝化细菌
亚硝酸盐
自养
活性污泥模型
异养
活性污泥
环境化学
生物量(生态学)
化学
反硝化细菌
反硝化
细菌
食品科学
生物
环境工程
生态学
氮气
污水处理
环境科学
硝酸盐
有机化学
遗传学
作者
Mohamad-Javad Mehrani,Przemysław Kowal,Dominika Sobotka,Martyna Godzieba,Sławomir Ciesielski,Jianhua Guo,Jacek Mąkinia
标识
DOI:10.1016/j.scitotenv.2022.161084
摘要
The second step of nitrification can be mediated by nitrite oxidizing bacteria (NOB), i.e. Nitrospira and Nitrobacter, with different characteristics in terms of the r/K theory. In this study, an activated sludge model was developed to account for competition between two groups of canonical NOB and comammox bacteria. Heterotrophic denitrification on soluble microbial products was also incorporated into the model. Four 5-week washout trials were carried out at dissolved oxygen-limited conditions for different temperatures (12 °C vs. 20 °C) and main substrates (NH4+-N vs. NO2--N). Due to the aggressive reduction of solids retention time (from 4 to 1 d), the biomass concentrations were continuously decreased and stabilized after two weeks at a level below 400 mg/L. The collected experimental data (N species, biomass concentrations, and microbiological analyses) were used for model calibration and validation. In addition to the standard predictions (N species and biomass), the newly developed model also accurately predicted two microbiological indicators, including the relative abundance of comammox bacteria as well as nitrifiers to heterotrophs ratio. Sankey diagrams revealed that the relative contributions of specific microbial groups to N conversion pathways were significantly shifted during the trial. The contribution of comammox did not exceed 5 % in the experiments with both NH4+-N and NO2--N substrates. This study contributes to a better understanding of the novel autotrophic N removal processes (e.g. deammonification) with nitrite as a central intermediate product.
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