摘要

       粪便处理技术正在迅速发展，以尽量减少周围环境的富营养化，并有可能减少抗生素和抗生素抗性基因 (ARG) 向环境中的引入。虽然实验室和中试规模的粪便处理系统拥有良好的结果，但尚未评估接收连续粪便输入的全面系统中抗生素和 ARG 的去除情况。治疗对 ARGs 的影响同样缺乏。本研究检查了在接收连续粪便和抗生素输入的全尺寸高级厌氧消化器 (AAD) 中磺胺类、四环素、四环素降解产物和相关 ARG 的发生和转化。在整个 AAD 系统中收集粪便样品以评估基线抗生素和 ARG 输入（原始粪便）、卫生化（巴氏消毒后的粪便）和厌氧消化（消化后的粪便）对抗生素和 ARG 水平的影响。通过液相色谱-串联质谱 (LC-MS/MS) 分析抗生素，并通过定量聚合酶链反应 (Q-PCR) 分析 ARG tet(O)、tet(W)、sul1 和 sul2。在处理后的粪便液体中观察到金霉素、土霉素、四环素及其降解产物的浓度显着降低（p<0.001），伴随着粪便固体的显着增加（p<0.001）。这些结果表明吸附是 AAD 期间四环素的主要去除途径。粪肥固体中金霉素和四环素的差向异构体与总残留物比率的显着降低进一步表明降解是解吸受限的。此外，在不使用磺胺类抗生素的情况下，AAD 后 sul1 和 sul2 拷贝显着减少（p<0.001），而四环素抗性基因保持不变。此外，还对利用自然曝气和液固分离处理的奶牛场进行了横断面研究，以比较 AAD 中抗生素和 ARG 的水平与普通粪便管理系统中的水平。不同农场之间生粪中抗生素的浓度差异很大，而观察到的 ARG 差异很小。然而，在来自三种不同粪便管理系统的污水中观察到抗生素和 ARGs（tet(W) 除外）水平的显着差异 (p<0.01)。

       Manure treatment technologies are rapidly developing to minimize eutrophication of surrounding environments and potentially decrease the introduction of antibiotics and antibiotic resistant genes (ARGs) into the environment. While laboratory and pilot-scale manure treatment systems boast promising results, antibiotic and ARG removals in full-scale systems receiving continuous manure input have not been evaluated. The effect of treatment on ARGs is similarly lacking. This study examines the occurrence and transformation of sulfonamides, tetracyclines, tetracycline degradation products, and related ARGs throughout a full-scale advanced anaerobic digester (AAD) receiving continuous manure and antibiotic input. Manure samples were collected throughout the AAD system to evaluate baseline antibiotic and ARG input (raw manure), the effect of hygenization (post-pasteurized manure) and anaerobic digestion (post-digestion manure) on antibiotic and ARG levels. Antibiotics were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the ARGs tet(O), tet(W), sul1 and sul2 were analyzed by quantitative polymerase chain reaction (Q-PCR). Significant reductions in the concentrations of chlortetracycline, oxytetracycline, tetracycline and their degradation products were observed in manure liquids following treatment (p < 0.001), concomitant to significant increases in manure solids (p < 0.001). These results suggest sorption is the major removal route for tetracyclines during AAD. Significant decreases in the epimer-to-total residue ratios for chlortetracycline and tetracycline in manure solids further indicate degradation is desorption-limited. Moreover, sul1 and sul2 copies decreased significantly (p < 0.001) following AAD in the absence of sulfonamide antibiotics, while tetracyclines-resistant genes remained unchanged. A cross-sectional study of dairy farms utilizing natural aeration and liquid-solid separation treatments was additionally performed to compare levels of antibiotics and ARGs found in AAD with the levels in common manure management systems. The concentration of antibiotics in raw manure varied greatly between farms while minimal differences in ARGs were observed. However, significant (p < 0.01) differences in the levels of antibiotics and ARGs (except tet(W)) were observed in the effluents from the three different manure management systems.

https://www.sciencedirect.com/science/article/abs/pii/S0269749117352260