The stereoselective biotransformation of methamphetamine (METH), as a chiral compound, during biological treatment in wastewater treatment plants (WWTPs) is often ignored. In this study, a non-racemic form of METH was detected in the raw influent of a full-scale WWTP, with S-(+)-METH as the predominant enantiomer. Stereoselective biotransformation of METH in favor of S-(+)-METH occurred in anaerobic/anoxic and aerobic processes, resulting in the detection of R-(-)-METH as the only enantiomer in the secondary sedimentation tank. To evaluate the stereoselective biotransformation of METH in an activated sludge system, controlled laboratory experiments were conducted under aerobic and anaerobic conditions. Different stereoselective enrichment was observed in a racemic METH batch experiment at various initial concentrations. Batch experiment results with different initial concentrations of nutrient substances demonstrated that the biotransformation of S-(+)-METH occurred simultaneously with the biodegradation of COD and NH₄⁺-N, proving its cometabolism nature. Enzymes released under microbial starvation stress likely stimulated R-(-)-METH biotransformation. Compared with the biotransformation rate of METH under the anaerobic condition, the presence of dissolved oxygen led to a higher biotransformation rate of METH under the aerobic condition.

甲基苯丙胺（METH）作为一种手性化合物，在废水处理厂（WWTP）的生物处理过程中的立体选择性生物转化常常被忽视。在这项研究中，在全规模污水处理厂的原始进水中检测到了非外消旋形式的冰毒，其中 S-(+)-冰毒是主要的对映体。 METH 的立体选择性生物转化有利于 S-(+)-METH，发生在厌氧/缺氧和好氧过程中，导致在二沉池中检测到 R-(-)-METH 作为唯一的对映体。为了评估活性污泥系统中冰毒的立体选择性生物转化，在好氧和厌氧条件下进行了受控实验室实验。在不同初始浓度的外消旋 METH 批量实验中观察到不同的立体选择性富集。不同营养物质初始浓度的批量实验结果表明，S-(+)-METH的生物转化与COD和NH ₄ ⁺ -N的生物降解同时发生，证明了其共代谢性质。微生物饥饿应激下释放的酶可能刺激 R-(-)-METH 生物转化。与厌氧条件下METH的生物转化率相比，溶解氧的存在导致有氧条件下METH的生物转化率更高。