Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore.
College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China.
Water Res. 2020 Oct 15;185:116156. doi: 10.1016/j.watres.2020.116156. Epub 2020 Aug 11.
Sulfamethoxazole (SMX) is a common antibiotic prescribed for treating infections, which is frequently detected in the effluent of conventional wastewater treatment plants (WWTPs). Its degradation and conversion in a laboratory-scale sulfur-based autotrophic denitrification reactor were for the first time investigated through long-term reactor operation and short-term batch experiments. Co-metabolism of SMX and nitrate by autotrophic denitrifiers was observed in this study. The specific SMX removal rate was 3.7 ± 1.4 μg/g SS-d, which was higher than those reported in conventional wastewater treatment processes. The removal of SMX by the enriched denitrifying sludge was mainly attributed to biodegradation. Four transformation products (three known with structures and one with unknown structure) were identified, of which the structures of the two transformation products (TPs) were altered in the isoxazole ring. Additionally, the presence of SMX significantly shaped the microbial community structures, leading to the dominant denitrifier shifting from Sulfuritalea to Sulfurimonas to maintain the stability of system. Collectively, the sulfur-based autotrophic denitrification process could effectively remove SMX in addition to efficient nitrate removal, and further polish the effluent from conventional WWTPs.
磺胺甲恶唑（SMX）是一种常用于治疗感染的常见抗生素，经常在传统污水处理厂（WWTP）的废水中被检测到。本研究通过长期反应器运行和短期批处理实验，首次研究了其在实验室规模的基于硫的自养反硝化反应器中的降解和转化。本研究观察到自养反硝化菌对 SMX 和硝酸盐的共代谢。特定的 SMX 去除率为 3.7±1.4μg/g SS-d，高于传统污水处理过程中的报道。富集的反硝化污泥对 SMX 的去除主要归因于生物降解。鉴定出了 4 种转化产物（3 种已知结构和 1 种未知结构），其中两种转化产物（TPs）的结构在异恶唑环中发生了改变。此外，SMX 的存在显著改变了微生物群落结构，导致优势脱氮菌从 Sulfuritalea 转向 Sulfurimonas，以维持系统的稳定性。总的来说，基于硫的自养反硝化工艺除了有效去除硝酸盐外，还可以有效地去除 SMX，并进一步改善传统 WWTP 的出水水质。
