Around 350 million tons of solid waste is disposed of in landfills every year globally, with millions of cubic meters of landfill leachates released into neighboring environment. However, to date, little is known about the variations of antimicrobial resistance (AMR) in on-site leachate treatment systems and its development in leachate-receiving water environment. Here, we quantified 7 subtypes of antibiotic resistance genes (ARGs), 3 types of culturable antibiotic resistant bacteria (ARB) and 6 subtypes of mobile genetic elements (MGEs) in the effluents from a combined leachate treatment process, including biological treatment (MBR), physical separation (UF), ultraviolet (UV) disinfection and advanced oxidation process (AOP). The contents of ARGs, ARB and MGEs were generally enriched by the MBR, but then decreased significantly along with the tertiary treatment process. However, in the effluent-receiving water samples, the abundance of dominant ARGs (i.e. ermB, sul1, bla_TEM) increased by 1.5 orders of magnitude within 96 h, alongside a general increase of MGEs (~10.0 log₁₀(copies/mL) and total ARB (~1100 CFU/mL). Structural correlation analyses reveal that target ARGs were closely associated with MGEs, particularly in effluent-receiving samples (Procrustes test; M² = 0.49, R = 0.71, P = 0.001); and occurrences of ARB were majorly affected by ARG's distribution and environmental conditions (e.g. nitrogen speciation) in effluent and recipient groups, respectively. This study indicates that current treatment technologies and operation protocols are not feasible in countering the development of AMR in effluent-receiving water environment, particularly in tidal rivers that are capable of retaining contaminants for a long residence time.

全球每年约有3.5亿吨固体废物被填埋，其中有数百万立方米的垃圾渗滤液被释放到附近的环境中。然而，迄今为止，关于现场渗滤液处理系统中抗微生物剂耐药性（AMR）的变化及其在渗滤液接收水环境中的发展知之甚少。在这里，我们量化了包括生物处理（MBR）在内的联合渗滤液处理过程中产生的废水中的7种亚型的抗生素抗性基因（ARG），3种可培养的抗药性细菌（ARB）和6种移动性遗传元件（MGEs）亚型，物理分离（UF），紫外线（UV）消毒和高级氧化工艺（AOP）。MBR通常会丰富ARG，ARB和MGE的含量，但随后随着三级处理过程而显着下降。但是，在接受废水的水样中，主要的ARGs丰富（即ermB，sul1，bla _TEM）在96 h内增加了1.5个数量级，同时MGE（〜10.0 log ₁₀（份/ mL）和总ARB（〜1100 CFU / mL））总体增加。 ARG与MGE密切相关，特别是在废水接收样品中（Procrustes测试； M ²  = 0.49，R  = 0.71，P = 0.001）；ARB的发生主要受ARG在污水处理组和接收组中的分布和环境条件（例如氮形成）的影响。这项研究表明，目前的处理技术和操作方案在应对污水接收水环境中AMR的发展方面是不可行的，特别是在能够长时间保留污染物的潮汐河中。