National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
Department of Botany and Microbiology, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
Sci Total Environ. 2024 Sep 15;943:173674. doi: 10.1016/j.scitotenv.2024.173674. Epub 2024 May 31.
This paper investigated the operational characteristics and self-regulation mechanism of the partial denitrification/anammox (PD/A) granular system under the stress of oxytetracycline (OTC), an emerging pollutant that accumulates in municipal wastewater treatment plants through various pathways, posing significant challenges for its future promotion in engineering applications. The results indicated that OTC concentrations below 100 mg/L intensified its short-term inhibition on the PD/A granular sludge system, decreasing functional bacterial activity, while between 150 and 300 mg/L, PD's NO-N to NO-N conversion ability diminished, and Anammox activity was significantly suppressed. Under long-term high OTC stress (20-30 mg/L), nitrogen removal suffered, and batch tests revealed significant inhibition of PD's NO-N to NO-N conversion, dropping from 73.77 % to 50.17 %. Anammox bacteria activity sharply declined from 1.81 to 0.39 mg N/gVSS/h under OTC stress. Extracellular polymeric substances (EPS) content rose from 185.39 to 210.86 mg/gVSS, indicating PD/A sludge's self-protection mechanism. However, EPS content fell due to cell lysis at high OTC (30 mg/L). The decreasing relative abundance of Candidatus_Brocadia (2.32 % to 0.93 %) and Thaure (12.63 % to 7.82 %) was a key factor in the gradual deterioration of denitrification performance. This study was expected to provide guidance for the PD/A process to cope with the interference of antibiotics and other emerging pollutants (short-term shock and long-term stress).
本文研究了在新兴污染物土霉素（OTC）的胁迫下部分反硝化/厌氧氨氧化（PD/A）颗粒系统的运行特性和自我调节机制。OTC 作为一种通过多种途径在城市污水处理厂中积累的污染物，对其未来在工程应用中的推广构成了重大挑战。结果表明，当 OTC 浓度低于 100mg/L 时，会短期抑制 PD/A 颗粒污泥系统，降低功能细菌的活性；而在 150-300mg/L 之间时，PD 的 NO-N 向 NO-N 的转化能力减弱，同时厌氧氨氧化活性受到显著抑制。在长期高 OTC 胁迫（20-30mg/L）下，氮去除受到影响，批式实验表明 PD 的 NO-N 向 NO-N 的转化受到显著抑制，从 73.77%下降至 50.17%。在 OTC 胁迫下，厌氧氨氧化细菌的活性从 1.81 急剧下降至 0.39mgN/gVSS/h。胞外聚合物（EPS）含量从 185.39mg/gVSS 上升至 210.86mg/gVSS，表明 PD/A 污泥具有自我保护机制。然而，在高 OTC（30mg/L）下，由于细胞裂解，EPS 含量下降。Candidatus_Brocadia（从 2.32%降至 0.93%）和 Thaurea（从 12.63%降至 7.82%）相对丰度的降低是导致脱氮性能逐渐恶化的关键因素。本研究期望为 PD/A 工艺应对抗生素和其他新兴污染物（短期冲击和长期胁迫）的干扰提供指导。
