School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China; Technical Center of Sewage Treatment Industry in Gansu, Lanzhou 730070, China.
School of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
J Hazard Mater. 2024 Oct 5;478:135430. doi: 10.1016/j.jhazmat.2024.135430. Epub 2024 Aug 4.
The intensive use of various antibiotics for clinical and agricultural purposes has resulted in their widespread use in wastewater treatment plants. However, little research has been conducted on the effects of antibiotics on nitrite accumulation, antibiotic degradation pathways, or the microbial community structure in nitrification systems. In this study, a laboratory-scale sequencing batch reactor was used to treat wastewater containing cefalexin (CFX) at different doses (5, 10, 15, and 20 mg/L). The results showed that the nitrification performance was gradually inhibited with increasing CFX concentration. Ammonia-oxidizing bacteria (AOB) are more tolerant to CFX than nitrite-oxidizing bacteria (NOB). Under 15 mg/L of CFX, NOB were completely suppressed, whereas AOB were partially inhibited, as evidenced by an ammonium removal efficiency of 60 % and a 90 % of nitrite accumulation ratio. The partial nitritation was achieved. CFX can be degraded into 2-hydroxy-3phenylpyrazine and cyclohexane through bacterial co-metabolism, and CFX degradation gradually diminishes with decreasing nitrification performance. The abundance of Nitrospira gradually decreased with increasing CFX concentration. Ferruginibacter, Hydrogenophaga, Thauera, and Pseudoxanthomonas were detected at relative abundances of 13.2 %, 0.4 %, 0.9 %, and 1.3 %, respectively, indicating their potential roles in antibiotic degradation. These findings provide insight into the interactions between antibiotics and microbial communities, which are beneficial for a better understanding of antibiotic degradation in nitrification systems.
抗生素在临床和农业上的大量应用导致其在废水处理厂中广泛使用。然而，对于抗生素对亚硝酸盐积累的影响、抗生素降解途径或硝化系统中微生物群落结构的影响，研究甚少。本研究采用实验室规模的序批式反应器，以头孢氨苄（CFX）为目标抗生素，在不同剂量（5、10、15 和 20mg/L）下处理含有 CFX 的废水。结果表明，硝化性能随 CFX 浓度的增加而逐渐受到抑制。氨氧化菌（AOB）比亚硝酸盐氧化菌（NOB）对 CFX 的耐受性更强。在 15mg/L 的 CFX 下，NOB 被完全抑制，而 AOB 被部分抑制，表现为氨去除效率为 60%和亚硝酸盐积累率为 90%。实现了部分亚硝化。CFX 可通过细菌共代谢降解为 2-羟基-3-苯基吡嗪和环己烷，随着硝化性能的降低，CFX 降解逐渐减少。Nitrospira 的丰度随 CFX 浓度的增加而逐渐降低。在相对丰度为 13.2%、0.4%、0.9%和 1.3%的 Ferruginibacter、Hydrogenophaga、Thauera 和 Pseudoxanthomonas 被检测到，表明它们在抗生素降解中具有潜在作用。这些发现深入了解了抗生素与微生物群落之间的相互作用，有助于更好地理解硝化系统中抗生素的降解。
