Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin, 300384, PR China.
Tianjin Academy of Eco-Environmental Sciences, Nankai, Tianjin, 300191, China.
J Environ Manage. 2023 Apr 15;332:117427. doi: 10.1016/j.jenvman.2023.117427. Epub 2023 Feb 2.
To remove residual nitrate from anammox process and achieve efficient nitrogen removal, a two-stage system (TAS) with the two individual reactors and a one-stage system (OAS) with the spatial functional areas in one reactor were established via anammox coupling sulfur autotrophic denitrification. The total nitrogen removal efficiency (TNRE) of OAS system (97.85 ± 1.92%) was higher than that of TAS system (93.63 ± 1.87%) under the influent NH-N and NO-N of 227 and 300 mg/L. Meanwhile, the responses of microbial metabolism to high nitrogen load were investigated in term of microbial metabolites, electron transfer and metabolic activity. Microbial metabolites characteristics demonstrated that the OAS system secreted more EPS with lower protein (PN)/polysaccharide (PS) ratio than that in the TAS system, which was beneficial to protect bacteria from high nitrogen load. Electrochemical analysis suggested that the secretion of electron conductive substance (such as PN, PS) and redox active substances (such as flavin mononucleotide, the binding of flavins and cytochrome c on the outer membrane) were increased in the OAS system, which promoted the electron transfer efficiency. Moreover, the electron transport system activity (ETSA) values and ATP contents in OAS system were higher than that in the TAS system, which indicated that metabolic activity was improved in OAS system under the stimulation of high nitrogen load. Additionally, the bacterial community analysis indicated that the functional bacteria of Candidatus_Kuenenia and Armatimonadetes_gp5 had higher abundance in the OAS system than that in the TAS system, which was beneficial to realize the stable nitrogen removal performance. Overall, the responses mechanism of the OAS system was established to explain the resistant to high nitrogen load.
为了去除厌氧氨氧化工艺中的残留硝酸盐并实现高效脱氮，通过厌氧氨氧化与硫自养反硝化耦合，建立了两段式系统（TAS）和一体式系统（OAS）。在进水 NH-N 和 NO-N 分别为 227 和 300 mg/L 的条件下，OAS 系统（97.85±1.92%）的总氮去除效率（TNRE）高于 TAS 系统（93.63±1.87%）。同时，从微生物代谢物、电子传递和代谢活性等方面研究了微生物代谢对高氮负荷的响应。微生物代谢物特征表明，OAS 系统分泌的 EPS 具有更低的蛋白（PN）/多糖（PS）比，有利于保护细菌免受高氮负荷的影响。电化学分析表明，OAS 系统中电子导电物质（如 PN、PS）和氧化还原活性物质（如黄素单核苷酸、外膜上黄素与细胞色素 c 的结合）的分泌增加，促进了电子传递效率。此外，OAS 系统中的电子传递系统活性（ETSA）值和 ATP 含量均高于 TAS 系统，表明在高氮负荷的刺激下，OAS 系统的代谢活性得到了提高。此外，细菌群落分析表明，OAS 系统中 Candidatus_Kuenenia 和 Armatimonadetes_gp5 的功能细菌丰度高于 TAS 系统，有利于实现稳定的脱氮性能。总之，建立了 OAS 系统的响应机制，以解释其对高氮负荷的抗性。
