Benzalkonium chlorides (BACs) are quaternary ammonium compounds (QUATs) used as biocides. The degradation of these compounds in wastewater treatment plants is essential to reduce their spread into the environment and thus prevent the development of QUAT-resistant genes. The biodegradation of two BACs (BAC-12 and BAC-14) was investigated in moving bed biofilm reactors (MBBRs). Degradationhalf-lifes of 12 and 20 hours for BAC-12 and -14, respectively, were detected as well as the formation of 42 metabolites. Two new degradation pathways for the BACs were identified in this study: 1) one involving an ω-oxidation, followed by β-oxidation and 2) one via an ω-oxidation followed by an α-oxidation that was succeeded by β-oxidation. Similar metabolites were detected for both BAC-12 and BAC-14. Additionalmetabolites were detected in the study, that could not be assigned to the above-mentioned pathways, revealing even more metabolic pathways in the MBBR which is probably due to the complexity of the microbial community in the biofilm. Interestingly, both TP194 (Benzyl-(carboxymethyl)-dimethylazanium) and TP208B (Benzyl-(2-carboxyethyl)-dimethylazanium) were identified as end products of the ω/β-pathway and the α/β-pathway. TP208B, TP152 and TP250 that were identified in this study, as well as the known BDMA were discovered in the effluent of a wastewater treatment plant.

苯扎氯铵 (BAC) 是用作杀菌剂的季铵化合物 (QUAT)。这些化合物在废水处理厂中的降解对于减少它们向环境中的扩散至关重要，从而防止 QUAT 抗性基因的产生。在移动床生物膜反应器 (MBBR) 中研究了两种 BAC（BAC-12 和 BAC-14）的生物降解情况。检测到 BAC-12 和 -14 的降解半衰期分别为 12 小时和 20 小时，并形成 42 种代谢物。本研究确定了 BAC 的两种新降解途径：1）一种涉及 ω-氧化，然后是 β-氧化；2）一种是先进行 ω-氧化，然后进行 α-氧化，然后进行 β-氧化。 BAC-12 和 BAC-14 均检测到类似的代谢物。研究中检测到了其他代谢物，这些代谢物无法归属于上述途径，揭示了 MBBR 中更多的代谢途径，这可能是由于生物膜中微生物群落的复杂性所致。有趣的是，TP194（苄基-（羧甲基）-二甲基氮氮盐）和TP208B（苄基-（2-羧乙基）-二甲基氮氮盐）均被鉴定为ω/β-途径和α/β-途径的终产物。本研究中鉴定出的 TP208B、TP152 和 TP250 以及已知的 BDMA 在废水处理厂的废水中被发现。