Zhang Feiyu, Cheng Shuqian, Zhao Jinbo, Li Anjie
Key Laboratory for Water and Sediment Science, Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
Key Laboratory for Water and Sediment Science, Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
J Environ Manage. 2023 Dec 15;348:119194. doi: 10.1016/j.jenvman.2023.119194. Epub 2023 Oct 11.
Even after pre-treatment, livestock and poultry wastewater still contain high concentrations of ammonia and residual antibiotics. These could be removed economically using the aerobic granular sludge (AGS) process with zero-valent iron (ZVI). The interaction of antibiotics and nitrogen in this process needs to be clarified and controlled, however, to achieve good removal performance. Otherwise, antibiotics might generate transformation products (TPs) with higher toxicity and lead to the emergence of antibiotic-resistant bacteria carrying antibiotic resistance genes (ARGs), which could cause persistent toxicity and the risk of disease transmission to the ecological environment. This study investigated the impact of ZVI on AGS for nitrogen and sulfamethoxazole (SMX) removal. The results show that AGS could maintain good ammonia removal performance and that the existence of SMX had a negative impact on ammonia oxidation activities. ZVI contributed to an increase in the abundance of nitrite oxidation bacteria, denitrifying bacteria and the functional genes of nitrogen removal. This led to better total nitrogen removal and a decrease in NO emission. Accompanied by biological nitrogen transformation, SMX could be transformed into 14 TPs through five pathways. ZVI has the potential to enhance transformation pathways with TPs of lower ecotoxicity, thereby reducing the acute and chronic toxicity of the effluent. Unfortunately, ZVI might enhance the abundance of sul1, sul2, and sul3 in AGS, which increases the risk of sulfonamide antibiotic resistance. In AGS, Opitutaceae, Xanthomonas, Spartobacteria and Mesorhizobium were potential hosts for ARGs. This study provides theoretical references for the interaction of typical antibiotics and nitrogen in the biological treatment process of wastewater and bioremediation of natural water bodies.
即使经过预处理，畜禽废水仍含有高浓度的氨和残留抗生素。使用零价铁（ZVI）的好氧颗粒污泥（AGS）工艺可以经济地去除这些物质。然而，为了实现良好的去除性能，需要阐明并控制该过程中抗生素与氮的相互作用。否则，抗生素可能会产生毒性更高的转化产物（TPs），并导致携带抗生素抗性基因（ARGs）的抗生素抗性细菌出现，这可能会造成持续毒性以及疾病传播到生态环境的风险。本研究调查了ZVI对AGS去除氮和磺胺甲恶唑（SMX）的影响。结果表明，AGS可以保持良好的氨去除性能，并且SMX的存在对氨氧化活性有负面影响。ZVI有助于增加亚硝酸盐氧化细菌、反硝化细菌的丰度以及氮去除功能基因。这导致了更好的总氮去除和NO排放的减少。伴随着生物氮转化，SMX可以通过五条途径转化为14种TPs。ZVI有潜力增强具有较低生态毒性TPs的转化途径，从而降低出水的急性和慢性毒性。不幸的是，ZVI可能会增加AGS中sul1、sul2和sul3的丰度，这增加了磺胺类抗生素抗性的风险。在AGS中，疣微菌科、黄单胞菌属、芽单胞菌纲和中生根瘤菌属是ARGs的潜在宿主。本研究为废水生物处理过程中典型抗生素与氮的相互作用以及天然水体的生物修复提供了理论参考。
