Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Joint Research Institute for New Energy and the Environment, East China Normal University and Colorado State University, Shanghai 200062, China.
Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China.
Environ Int. 2018 May;114:143-151. doi: 10.1016/j.envint.2018.02.049. Epub 2018 Mar 2.
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) increased by 1.5 orders of magnitude within 96 h, alongside a general increase of MGEs (10.0 log(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; M = 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.
每年全球有大约 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周边环境中。然而，迄今为止，人们对现场渗滤液处理系统中抗生素抗性（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，我们量化了生物处理（MBR）、物理分离（UF）、紫外线（UV）消毒和高级氧化过程（AOP）相结合的渗滤液处理过程中流出物中的 7 种抗生素抗性基因（ARGs）亚型、3 种可培养抗生素抗性细菌（ARB）和 6 种移动遗传元件（MGEs）。MBR 通常会使 ARGs、ARB 和 MGEs 的含量增加，但随着三级处理过程的进行，其含量会显著降低。然而，在出水接收水样中，优势 ARGs（即 ermB、sul1、bla）的丰度在 96 小时内增加了 1.5 个数量级，同时 MGEs（10.0 log(copies/mL)和总 ARB（1100 CFU/mL）也普遍增加。结构相关分析表明，目标 ARGs 与 MGEs 密切相关，特别是在出水接收样本中（普罗克鲁斯测试；M=0.49，R=0.71，P=0.001）；而 ARB 的出现主要受到 ARG 在出水和接收组中的分布和环境条件（如氮形态）的影响。本研究表明，当前的处理技术和操作方案在应对出水接收水环境中 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流中。
