Frequent occurrence of trace antibiotics in reclaimed water is concerning, which inevitably causes aquifer contamination in the case of managed aquifer recharge (MAR). Global governments have formulated strict reclaimed water standards to ensure the safety of water reuse. Recent studies have found that improved antibiotics removal is intimately associated with high ammonia-oxidizing activity. However, the role of NH4+-N in the removal of residual antibiotics of reclaimed water during MAR remains unknown. NH4+-N removal and the effects of ammonia oxidation on antibiotics biodegradation in the aquifer are the most significant facts for solving the above collision. In this work, the effects of NH4+-N (0, 1 and 5 mg/L) in a model refractory antibiotic (oxacillin (OXA), 100 μg/L) attenuation were deciphered by employing three individual simulated MAR columns, which so called N0, N1 and N5. The results showed that 5 mg/L NH4+-N in influent upregulated the abundance of amo genes by 28.9 %-68.0 % in N5. And the enriched functional genes encoding key degradation enzymes enhanced the OXA removal by 18.7 % and alleviated the oxidative stress caused by antibiotics. Subsequently, antibiotic resistance genes (ARGs), mobile gene elements (MGEs) and human bacterial pathogens (HBPs) abundance were all significantly decreased. Moreover, the intimate association between ammonia-oxidizing microorganisms (AOM) and candidate OXA degraders based on microbial network analysis further supported the significance of AOM on OXA biodegradation. This study provides comprehensive evidence that appropriate amounts of NH4+-N are beneficial in antibiotics and antibiotic resistance risk reduction, providing compelling insights for refine NH4+-N recharge limitation.

中文翻译：

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NH4+-N 在管理含水层补给过程中去除苯唑西林中的关键作用：重新考虑补给限制


再生水中频繁出现微量抗生素令人担忧，在管理含水层补给 （MAR） 的情况下，这不可避免地会导致含水层污染。全球政府制定了严格的再生水标准，以确保水回用的安全性。最近的研究发现，抗生素去除率的提高与高氨氧化活性密切相关。然而，NH4+-N 在 MAR 期间去除再生水中残留抗生素的作用仍然未知。NH4+-N 的去除和氨氧化对含水层中抗生素生物降解的影响是解决上述碰撞的最重要事实。在这项工作中，通过使用三个单独的模拟 MAR 柱（即 N0、N1 和 N5）破译了 NH4+-N（0、1 和 5 mg/L）在模型难治性抗生素 （OXA），100 μg/L）衰减中的影响N0、N1 和 N5。结果表明，进水中 5 mg/L NH4+-N 使 N5 中 amo 基因的丰度上调了 28.9 %—68.0 %。编码关键降解酶的富集功能基因将 OXA 去除率提高了 18.7%，并减轻了抗生素引起的氧化应激。随后，抗生素耐药基因 （ARGs） 、移动基因元件 （MGEs） 和人类细菌病原体 （HBP） 丰度均显著降低。此外，基于微生物网络分析的氨氧化微生物 （AOM） 与候选 OXA 降解剂之间的密切联系进一步支持 AOM 对 OXA 生物降解的重要性。本研究提供了全面的证据，证明适量的 NH4+-N 有利于抗生素和降低抗生素耐药性风险，为改进 NH4+-N 充电限制提供了令人信服的见解。