Light Irradiation Enables Rapid Start-Up of Nitritation through Suppressing nxrB Gene Expression and Stimulating Ammonia-Oxidizing Bacteria,Environmental Science & Technology

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Light Irradiation Enables Rapid Start-Up of Nitritation through Suppressing nxrB Gene Expression and Stimulating Ammonia-Oxidizing Bacteria
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2021-09-16 , DOI: 10.1021/acs.est.1c04174
Lingfeng Wang ₁ , Shuang Qiu ₁ , Jianhua Guo ₂ , Shijian Ge ₁

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Nitritation facilitates the application of anaerobic ammonium oxidation (Anammox)-based processes for cost-efficient nitrogen removal from wastewater. This study proposed light irradiation as a novel strategy to rapidly start up nitritation by stimulating both the activities and growth of ammonia-oxidizing bacteria (AOB) while suppressing that of nitrite-oxidizing bacteria (NOB). Batch assays and kinetic model jointly suggested that AOB activity presented an initial increase followed by a decline while NOB decreased continuously throughout the light energy densities applied. Under optimal light energy densities (0.03–0.08 kJ/mg VSS), the highest nitrite accumulation ratio of 70.0% was achieved in sequencing batch reactors with both mainstream online and sidestream offline light treatments when treating real or synthetic municipal wastewater. Light irradiation induced different responses of AOB and NOB, leading to microbial structure optimization. Specifically, the expression of nxrB was downregulated, while the expression of amoA was upregulated under appropriate light irradiation. Moreover, although Nitrosomonas as typical AOB disappeared, the family Nitrosomonadaceae was doubled with enrichment of Ellin6067 and another four Nitrosomonadaceae genera that were only identified in light-treated reactors, thus ensuring AOB predominance and stable nitritation. These findings offer a new approach to rapidly establishing nitritation using light irradiation in municipal wastewater, especially for nitritation/microalgae system.

中文翻译：

光照射通过抑制 nxrB 基因表达和刺激氨氧化细菌使硝化作用快速启动

亚硝化促进了基于厌氧氨氧化 (Anammox) 的工艺的应用，以经济高效地从废水中去除氮。这项研究提出了光照射作为一种通过刺激氨氧化细菌 (AOB) 的活性和生长同时抑制亚硝酸盐氧化细菌 (NOB) 的活性和生长来快速启动亚硝酸化的新策略。批量分析和动力学模型共同表明，AOB 活性呈现初始增加然后下降，而 NOB 在整个应用的光能密度中持续下降。在最佳光能密度 (0.03–0.08 kJ/mg VSS) 下，在处理真实或合成城市废水时，采用主流在线和侧流离线光处理的序批式反应器实现了 70.0% 的最高亚硝酸盐积累率。光照射诱导 AOB 和 NOB 的不同反应，导致微生物结构优化。具体来说，表达式为nxrB被下调，而amoA 的表达在适当的光照射下被上调。此外，尽管亚硝化单胞作为典型AOB消失，家庭Nitrosomonadaceae用富集一倍Ellin6067和另外四个Nitrosomonadaceae属即只在光处理的反应器识别，从而确保AOB优势和稳定亚硝化。这些发现提供了一种在城市废水中使用光照射快速建立亚硝化的新方法，特别是对于亚硝化/微藻系统。

更新日期：2021-10-06

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