4种磺胺类药物及乙酰化代谢物在污水处理厂的去除及机制

乙酰化代谢物是磺胺类药物的重要代谢产物.为研究4种常见磺胺类药物及其乙酰化代谢物在污水厂中的去除机制,根据污水停留时间采集厦门某A2/O型工艺污水厂不同处理单元的污水和污泥样品,采用固相萃取-高效液相色谱串联质谱法检测目标化合物.结果显示,8种目标物中有6种在水体中被检测出,污泥中有5种目标物被检测出.计算总去除率及各个处理单元间的去除率,结果表明,磺胺二甲基嘧啶在污水厂中总去除率几乎为0,而其他5种化合物都有不同程度的去除,但不同目标物在各处理单元的去除率不同.利用质量平衡,分析各物质可能的去除机制,磺胺二甲基嘧啶可能去除机制为污泥吸附,磺胺嘧啶、磺胺甲基嘧啶和磺胺甲唑可能的去除机制均为生物降解.

Removal Efficiencies and Mechanism Research on Four Sulfonamides and Their Acetyl Metabolites in a Wastewater Treatment Plant

Acetyl metabolites are the major metabolites of sulfonamides. In order to investigate the removal mechanism of four commonly used sulfonamides and their metabolites in wastewater treatment plants, sulfonamides and their corresponding acetyl metabolites in wastewater and sludge in a wastewater treatment plant equipped with A²/O in Xiamen City were sampled. Sample selection was based on the hydraulic retention time. Solid phase extraction followed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was applied to analyze the target compounds. Results showed that six out of eight of the target compounds were detected in the wastewater, while five were detected in the sludge. Based on the removal efficiencies overall and of the different compartments, the concentration of sulfamethazine was almost unchanged during wastewater treatment plant (WWTP) processes, the other sulfonamides were removed with different removal efficiencies. Removal efficiencies varied for every compartment. The potential removal pathways were analyzed based on the mass balance of the target compounds. The removal pathway of sulfamethazine was sludge adsorption, while the potential removal mechanism of sulfamerazine, sulfadiazine, and sulfamethoxazole was biodegradation.