Abstract：
Face masks have emerged as a significant source of microplastics (MPs) under the influence of biotic and abiotic interactions. However, the combined effects of abiotic photoaging and biofilm-loading on mask-derived MPs as carriers of metal ions are not clear. We investigated the Pb(Ⅱ) adsorption onto polypropylene (PP) and polyurethane (PU) mask-derived MPs treated by photoaging, biofilm-loading, and both combinations, evaluating the composite risks. PU mask-derived MPs (1.157.47 mg/g) exhibited greater Pb(Ⅱ) adsorption capacity than PP mask-derived MPs (0.842.08 mg/g) because of the presence of intrinsic carbonyl functional groups. Photoaging (30.5%, 88.4%), biofilm-loading (110.7%, 87.1%), and both combinations (146.7%, 547.0%) of PP and PU masks enhanced Pb(Ⅱ) adsorption compared to virgin mask-derived MPs due to the increase of oxygen-containing functional groups. High-throughput sequencing indicated that the structural morphology and chemical composition of masks significantly affected the microbial community. Adsorption mechanisms involved electrostatic force and surface complexation. A combination of photoaging and biofilms increased the ecological risk index of mask-derived MPs in freshwater, showing the risk level to be high (PP mask) and very high (PU mask). This research highlights the crucial role of photoaging combined with biofilms in controlling metal ion adsorption onto mask-derived MPs, thereby increasing the composite risks.
摘要：
在生物和非生物相互作用的影响下，口罩已成为微塑料（MPs）的重要来源。然而,非生物光老化和生物膜负载对作为金属离子载体的掩模衍生MPs的联合影响尚不清楚。我们研究了通过光老化处理的聚丙烯（PP）和聚氨酯（PU）掩模衍生的MPs对Pb（Ⅱ）的吸附，生物膜负载，和两种组合，评估综合风险。由于固有的羰基官能团的存在，PU掩模衍生的MPs（1.157.47mg/g）比PP掩模衍生的MPs（0.842.08mg/g）具有更大的Pb（Ⅱ）吸附能力。光老化（30.5%，88.4%)，生物膜载量(110.7%，87.1%)，和两种组合(146.7%，547.0％）的PP和PU掩模与原始掩模衍生的MPs相比，由于含氧官能团的增加，增强了Pb（Ⅱ）的吸附。高通量测序表明，口罩的结构形态和化学组成对微生物群落有显著影响。吸附机制涉及静电力和表面络合。光老化和生物膜的结合增加了淡水中面具衍生的MPs的生态风险指数，显示风险水平高(PP面罩)和非常高(PU面罩)。这项研究强调了光老化与生物膜结合在控制金属离子吸附到掩模衍生的MPs上的关键作用，从而增加了复合风险。
