Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094, Jiangsu, P. R. China.
Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
Environ Sci Technol. 2021 Oct 5;55(19):13297-13305. doi: 10.1021/acs.est.1c04174. Epub 2021 Sep 16.
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 was downregulated, while the expression of was upregulated under appropriate light irradiation. Moreover, although as typical AOB disappeared, the family was doubled with enrichment of and another four 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.
亚硝化作用促进了基于厌氧氨氧化（Anammox）的工艺在废水脱氮中的应用，该工艺具有成本效益。本研究提出了一种新策略，即利用光照刺激氨氧化细菌（AOB）的活性和生长，同时抑制亚硝酸盐氧化细菌（NOB）的活性，从而快速启动亚硝化作用。批式实验和动力学模型共同表明，AOB 活性在光照能密度应用过程中先增加后减少，而 NOB 则持续减少。在最优光照能密度（0.03-0.08 kJ/mg VSS）下，当处理实际或合成城市污水时，主流在线和侧流离线光照处理的序批式反应器中实现了 70.0%的最高亚硝酸盐积累比。光照诱导了 AOB 和 NOB 的不同反应，导致微生物结构的优化。具体来说，在适当的光照下， 的表达下调，而 的表达上调。此外，尽管作为典型 AOB 的 消失了，但 家族的数量增加了一倍，并且在光照处理的反应器中富集了另外四个仅被鉴定为光照处理的 属，从而保证了 AOB 的优势地位和稳定的亚硝化作用。这些发现为在城市废水中利用光照快速建立亚硝化作用提供了一种新方法，特别是对于亚硝化/微藻系统。
