摘要
      抗生素抗性基因（ARGs）和纳米塑料（NP）已被确定为水环境中新出现的污染物；抗生素抗性质粒（ARPs）和NP之间的相互作用将影响沉积物中ARG的运输。本文对河流和湖泊沉积物中典型的ARP在聚苯乙烯纳米塑料（PS-NPs）上的吸附实验进行了研究，以阐明吸附机理和环境因素的影响。结果表明，PS NPs的吸附量随着剂量的增加而增加，而随着沉积物粒度的增加而减少。PS NPs的多层吸附主要存在于沙子和淤泥沉积物中，而填充吸附主要存在在粘土中。此外，吸附的PS NPs通过刺激静电力诱导的ARPs颗粒内扩散，增强了沉积物中ARPs的物理吸附。此外，ARPs在PS NP上的吸附量随着pH的增加而减少，并且由于静电排斥和竞争吸附的增强而溶解有机物。离子强度通过增加ARPs在PS NP上的静电吸引和吸附位点而起到催化作用。沉积物中吸附的ARPs与生物膜外/细胞内DNA中的ARGs密切相关，对ARGs的分布和增殖有很大影响。研究结果表明，纳米颗粒诱导的固液界面吸附可能会加剧ARG相关的污染，而固液界面吸附受pH、离子强度和溶解有机物的控制。这项研究为NP作为ARP载体在沉积物中的作用提供了补充见解，并促进了我们对NP-ARG在水生生态系统中共同发生污染的风险的理解。
Abstract
Antibiotic resistance genes (ARGs) and nanoplastics (NPs) have been identified as emerging pollutants in water environment; the interactions between antibiotic resistance plasmids (ARPs) and NPs will influence ARG transport in sediments. Herein, the adsorption experiments of a typical ARP onto polystyrene nanoplastics (PS-NPs) in river and lake sediments were conducted to elucidate the adsorption mechanisms and the effects of environmental factors. Results indicated that the adsorption amounts of PS-NPs increased with the dosages while decreased with the particle size of sediments. Multi-layer adsorption of PS-NPs was found to exist mainly in sand and silt sediments, whereas the filling adsorption dominated in the clay. Moreover, the adsorbed PS-NPs enhanced the physisorption of ARPs in sediments through stimulating the intraparticle diffusion of ARPs induced by electrostatic force. Besides, the adsorption amounts of ARPs onto the PS-NPs decreased with the increasing pH and dissolve organic matter due to the enhanced electrostatic repulsion and competitive adsorption. The ion strength played catalytic roles by increasing the electrostatic attraction and adsorption sites of ARPs on PS-NPs. The adsorbed ARPs in sediments were closely related with the ARGs in extra/intracellular DNA of biofilms, influencing the distribution and proliferation of ARGs largely. The findings indicate that ARG-associated pollution might be enhanced by the solid-liquid interface adsorption induced by NPs, which was controlled by pH, ion strength and dissolve organic matter. This study provides supplementary insights into the roles of NPs as carriers of ARP in sediments, and advances our understanding on the risks of NP-ARG co-occurring contamination in aquatic ecosystems.

https://www.sciencedirect.com/science/article/pii/S0269749122016700