Abstract:

Antibiotics are widely used in worldwide, and different antibiotics have been detected in many kinds of wastewater. In this study, take sulfamethoxazole (SMX) and oxytetracycline (OTC) as representatives to investigate their short-term (6 h) and long-term effects (22 d) on the Anammox process. The results showed that in the experimental concentrations (1, 10, 100, 1000 μg/L), the short-term inhibition threshold of OTC is 10 μg/L, and the long-term threshold is 1000 μg/L, which decreased the Anammox rate from 14.6 to 12.0 and 11.1 mg/(h·g SS), respectively. SMX in 1—1000 μg/L has no significant effect on Anammox biofilm. The Anammox biofilm responds more quickly to SMX than to OTC. It can secrete a large amount of extracellular polymer to resist SMX, and at the same time can induce denitrifying bacteria to degrade SMX. OTC increased the microbial diversity of Anammox biofilms, while SMX increased the abundance of dominant microorganisms and improved the relative abundance of denitrifying bacteria to 14.9% from 0.01%. Therefore, Anammox can treat wastewater containing trace amounts of SMX, and long-term domestication is required when treating wastewater containing OTC.

Key words: environment, wastewater, anaerobic, oxidation, bioreactors, biochemical engineering

摘要：

抗生素在世界范围内使用广泛，目前已经在多种废水中检测到了不同种类的抗生素。以磺胺甲唑（SMX）和土霉素（OTC）为代表，研究其对厌氧氨氧化过程的短期（6 h）和长期（22 d）影响。结果表明：在实验浓度中（1、10、100、1000 μg/L），OTC的短期抑制阈值为10 μg/L，将厌氧氨氧化活性由14.6降至12.0 mg/（h·g SS）；长期抑制阈值为1000 μg/L，将厌氧氨氧化活性降至11.1 mg/（h·g SS）；1~1000 μg/L的SMX对厌氧氨氧化生物膜无显著影响。厌氧氨氧化生物膜对SMX的响应比对OTC的响应更加快速，可以分泌大量的胞外聚合物以抵抗SMX，同时可以诱导反硝化菌降解SMX。OTC导致厌氧氨氧化生物膜的微生物多样性增加，而SMX则促使优势微生物的丰度增加，同时诱导反硝化菌的相对丰度从0.01%最高增加至14.9%，有助于抵抗SMX的抑制。因此，厌氧氨氧化可以处理含有微量SMX的废水，在处理含OTC的废水时，则需要经过长期驯化。

关键词: 环境, 废水, 厌氧, 氧化, 生物反应器, 生化工程