Abstract：
Microplastics (MPs) undergo aging over time, which can influence their behavior in the environment. While laboratory-simulated studies have investigated MP aging, research on natural aging in various real environments remains limited. This study aims to investigate the physical, chemical and biological changes that occur in five types of MPs after more than 10 months of natural aging in three different real environments: seawater, air and soil. Results are compared with previous laboratory experiments. The surface roughness of all types of aged MPs was found to be higher in seawater than in air and soil, which differed from previous simulated studies that showed the highest roughness in air. All aged MPs exhibited the occurrence of hydroxyl and carbonyl groups due to the oxidation processes. Interestingly, the MPs aged in soil showed the lowest level of these functional groups, while in seawater or air, some MPs demonstrated the highest. This contrasts with previous studies indicating the highest level of oxygen-containing functional groups in aged MPs in air. Bacterial analysis identified fourteen bacterial phyla on the surface of aged MPs in all three real environments, with varying abundance in specific environments. Notably, the composition of bacterial communities in the microplastisphere was determined by the surrounding environments, independent of MP types. Natural aging is more complex than laboratory simulations, and the degree of MP aging increases with the complexity of environmental factors. These findings enhance our understanding of the natural aging of MPs in different real environments.
摘要：
微塑料(MPs)会随着时间的推移而老化，这会影响他们在环境中的行为。虽然实验室模拟研究已经调查了MP老化，在各种真实环境中对自然衰老的研究仍然有限。这项研究旨在调查身体,在三种不同的真实环境中自然老化超过10个月后，五种类型的MP发生的化学和生物变化：海水，空气和土壤。将结果与先前的实验室实验进行比较。发现海水中所有类型的老化MP的表面粗糙度高于空气和土壤中的表面粗糙度。这不同于以前的模拟研究，显示空气中粗糙度最高。由于氧化过程，所有老化的MP都显示出羟基和羰基的出现。有趣的是,年龄在土壤中的国会议员显示出这些官能团的最低水平，在海水或空气中，一些议员表现得最高。这与先前的研究相反，该研究表明空气中老化的MP中含氧官能团的含量最高。细菌分析在所有三个真实环境中的老化MP表面上确定了14个细菌门，在特定环境中具有不同的丰度。值得注意的是,微质体中细菌群落的组成由周围环境决定，与MP类型无关。自然老化比实验室模拟更复杂，MP老化程度随环境因素的复杂性而增加。这些发现增强了我们对不同真实环境中MP自然老化的理解。
