摘要
      固相反硝化（SPD）已被用于污水处理厂的废水中，以提高硝酸盐的去除率，而废水中共存的抗生素是一个常见的环境问题。在本研究中，系统地研究了单微量磺胺甲恶唑（SMX）/甲氧苄啶（TMP）及其混合物对玉米芯支持的SPD系统中微生物脱氮性能、抗生素去除和抗生素抗性基因（ARGs）的影响。单用50µg/L的SMX或TMP可使平均脱氮率提高46.90%或61.09%，而混合使用SMX和TMP则没有显著的抑制作用。优势反硝化菌（Comamonadaceae科和Azospia）和发酵菌（Ancalomobium）的丰度与不同抗生素组的反硝化性能一致。单一的SMX和TMP获得了相对较高的反硝化基因和酶丰度。SMX和TMP混合提高了反硝化基因拷贝数，但降低了除EC 1.7.7.2外的关键反硝化酶。此外，单一抗生素组TMP的去除率（56.70%±3.18%）高于SMX（25.44%±2.62%），其他抗生素（即SMX或TMP）的存在对TMP或SMX的去除性能没有显著影响。生物降解是SMX和TMP的主要去除机理，污泥和玉米芯吸附对其去除作用不大。SMX具有磺胺耐药基因（SRGs）传播的风险。此外，网络分析表明，Niveibacterium和Bradyrhizobium是SRGs的潜在宿主，促进了ARGs的水平传播。
Abstract
Solid-phase denitrification (SPD) has been used in wastewater treatment plant effluent to enhance nitrate removal, and antibiotics co-existing in the effluent is a common environmental problem. In this study, it was systematically investigated the effect of single trace sulfamethoxazole (SMX)/trimethoprim (TMP) and their mixture on microbial denitrification performance, the antibiotics removal, and antibiotics resistance genes (ARGs) in corncob supported SPD system. The average denitrification rate was improved by 46.90% or 61.09% with single 50 µg/L SMX or TMP, while there was no significant inhibition with mixed SMX and TMP. The abundance of dominant denitrifiers (Comamonadaceae family and Azospia) and fermentation bacteria (Ancalomicrobium) were consistent with the denitrification performance of different antibiotics groups. Single SMX and TMP achieved relatively higher denitrification gene and enzyme abundance. Mixed SMX and TMP improved the denitrification gene copies, but they reduced the key denitrification enzymes except for EC 1.7.7.2. Additionally, the removal efficiency of TMP (56.70% ± 3.18%) was higher than that of SMX (25.44% ± 2.62%) in single antibiotic group, and the existence of other antibiotics (i.e. SMX or TMP) had no significant impact on the TMP or SMX removal performance. Biodegradation was the main removal mechanism of SMX and TMP, while sludge and corncob adsorption contributed a little to their removal. SMX had the risk of sulfanilamide resistance genes (SRGs) dissemination. Furthermore, network analysis indicated that Niveibacterium and Bradyrhizobium were the potential hosts of SRGs, which promoted the horizontal transmission of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S1001074222005095