Hu Chengcheng, Sun Xianyun, Zhang Long, Wang Hongzhi, Dong Liang, Li Shaojie
Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
J Environ Manage. 2023 Mar 15;330:117146. doi: 10.1016/j.jenvman.2022.117146. Epub 2022 Dec 30.
Bioaugmentation is considered as an attractive method for nitrogen removal in water treatment, but its effectiveness in actual high-strength piggery wastewater has not been adequately verified and the mechanism of bioaugmentation in actual wastewater treatment system is not very clear especially from the perspectives of microbial communities and functional genes. This study investigated the mechanisms of a heterotrophic nitrifying-aerobic denitrifying strain Alcaligenes aquatilis AS1 in the bioaugmentation of continuous biological nitrogen removal of actual piggery wastewater at laboratory scale. The addition of strain AS1 significantly improved the nitrogen removal efficiency (more than 95% of NH-N and 75% of TN were removed) and raised the activated sludge resistance to shock loading. AS1 addition also significantly shifted the microbiota structure and interactions among microbial networks were enhanced to obtain the stable bacterial communities. Moreover, strain AS1 achieved effective proliferation and long-term colonization in activated sludge with a relative abundance of genus Alcaligenes more than 70% during the whole operation process and played a dominant role in biological nitrogen removal, while different genera were respectively enriched and involved in pollutants removal at different stages in the control group. In addition, the abundances of most functional genes involved in carbon (C) degradation, carbon fixation and nitrogen (N), phosphorus (P), sulfur (S) cycling in activated sludge were significantly increased in reactor AS1, indicating that strain AS1 not only relied on its unique C and N metabolic activities, but also recruited microorganisms with diverse functions to jointly remove pollutants in wastewater, which could be a common bioaugmentation mechanism in open reactors. This study proves the promising application prospect of strain AS1 in the treatment of high-strength piggery wastewater and shows great importance for guiding bioaugmentation application of functional strains in practical wastewater treatment systems.
生物强化被认为是一种有吸引力的污水处理脱氮方法，但其在实际的高强度养猪废水中的有效性尚未得到充分验证，并且在实际污水处理系统中的生物强化机制尚不清楚，尤其是从微生物群落和功能基因的角度。本研究在实验室规模下，研究了异养硝化-好氧反硝化菌株嗜水气单胞菌AS1在实际养猪废水连续生物脱氮生物强化中的机制。添加菌株AS1显著提高了脱氮效率（NH-N去除率超过95%，TN去除率达到75%），并提高了活性污泥对冲击负荷的抗性。添加AS1还显著改变了微生物群落结构，增强了微生物网络之间的相互作用，从而获得了稳定的细菌群落。此外，菌株AS1在活性污泥中实现了有效增殖和长期定殖，在整个运行过程中嗜水气单胞菌属的相对丰度超过70%，并在生物脱氮中发挥主导作用，而对照组中不同属在不同阶段分别富集并参与污染物去除。此外，在反应器AS1中，活性污泥中参与碳（C）降解、碳固定以及氮（N）、磷（P）、硫（S）循环的大多数功能基因的丰度显著增加，这表明菌株AS1不仅依靠其独特的C和N代谢活动，还招募了具有不同功能的微生物共同去除废水中的污染物，这可能是开放反应器中常见的生物强化机制。本研究证明了菌株AS1在处理高强度养猪废水方面具有广阔的应用前景，对于指导功能菌株在实际污水处理系统中的生物强化应用具有重要意义。
