School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China.
School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China; Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha 410114, China.
Water Res. 2023 Aug 1;241:120120. doi: 10.1016/j.watres.2023.120120. Epub 2023 May 24.
Current research focuses on efficient single-stage nitrogen removal from organic matter wastewater using the partial nitritation-anammox (PNA) process. In this study, we constructed a single-stage partial nitritation-anammox and denitrification (SPNAD) system using a dissolved oxygen-differentiated airlift internal circulation reactor. The system was operated continuously for 364 days at 250 mg/L NH-N. During the operation, the COD/NH-N ratio (C/N) was increased from 0.5 to 4 (0.5, 1, 2, 3, and 4), and the aeration rate (AR) gradually increased. The results showed that the SPNAD system maintained efficient and stable operation at C/N = 1-2 and AR = 1.4-1.6 L/min, with an average total nitrogen removal efficiency of 87.2%. The removal pathways of pollutants in the system and the interactions between microbes were revealed by analyzing the changes in sludge characteristics and microbial community structure at different phases. As the influent C/N increased, the relative abundance of Nitrosomonas and Candidatus Brocadia decreased, and that of denitrifying bacteria, such as Denitratisoma, increased to 44%. The nitrogen removal pathway of the system gradually changed from autotrophic nitrogen removal to nitrification-denitrification. At the optimum C/N, the SPNAD system synergistically removed nitrogen through PNA and nitrification-denitrification. Overall, the unique reactor configuration facilitated the formation of dissolved oxygen compartments, providing a suitable environment for different microbes. An appropriate organic matter concentration maintained the dynamic stability of microbial growth and interactions. These enhance microbial synergy and enable efficient single-stage nitrogen removal.
目前的研究重点是使用部分亚硝化-厌氧氨氧化（PNA）工艺从有机物废水中高效地进行单级脱氮。在本研究中，我们使用溶解氧差异化气升式内循环反应器构建了一个单级部分亚硝化-厌氧氨氧化和反硝化（SPNAD）系统。该系统在 250mg/L NH-N 下连续运行了 364 天。在运行过程中，COD/NH-N 比（C/N）从 0.5 增加到 4（0.5、1、2、3 和 4），曝气量（AR）逐渐增加。结果表明，在 C/N=1-2 和 AR=1.4-1.6 L/min 时，SPNAD 系统能够保持高效稳定的运行，平均总氮去除效率为 87.2%。通过分析不同阶段污泥特性和微生物群落结构的变化，揭示了系统中污染物的去除途径和微生物之间的相互作用。随着进水 C/N 的增加，硝化菌（如 Nitrosomonas）和候选布鲁卡氏菌（Candidatus Brocadia）的相对丰度降低，反硝化菌（如 Denitratisoma）的相对丰度增加到 44%。系统的脱氮途径逐渐从自养脱氮转变为硝化-反硝化。在最佳 C/N 下，SPNAD 系统通过 PNA 和硝化-反硝化协同去除氮。总的来说，独特的反应器结构有利于溶解氧区的形成，为不同的微生物提供了适宜的环境。适当的有机物浓度保持了微生物生长和相互作用的动态稳定性。这些增强了微生物协同作用，实现了高效的单级脱氮。
