Abstract

Water pollution by non-biodegradable materials such as plastics is a major source of concern. Here, we investigated the ability of polyethylene terephthalate (PET), high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS) microplastics (MPs-4 mm) to adsorb benzo(a)pyrene (BaP) and pyrene (Pyr) in freshwater after 3 and 30 days. BaP was more adsorbed than Pyr with PP and PS being the most and least efficient adsorbents of BaP, respectively. In mixed solutions, the differences in PAHs adsorption are smoother than in pure solutions, and an increase in adsorbed PAHs half-life has been observed. In parallel, the ability of bacterial species isolated from freshwater responsible for infections in humans (Escherichia coli, Klebsiella pneumoniae and Aeromonas sobria) to assemble biofilms on plastics was evaluated. Biofilm assembly increased with time (1 to 3 months) being possible to observe biofilms on LDPE, HDPE and PS. For PET and PP only after 3 months on fragments of the original MPs was possible to observe attached bacteria. Exposure to 100 µg/mL PAHs (either isolated or mixed) during 1 month significantly decreased bacterial persistence (p < .01) compared to unexposed bacteria.

摘要

塑料等不可生物降解材料造成的水污染是一个主要问题。在这里，我们研究了聚对苯二甲酸乙二醇酯 (PET)、高密度聚乙烯 (HDPE)、低密度聚乙烯 (LDPE)、聚丙烯 (PP) 和聚苯乙烯 (PS) 微塑料 (MPs-4 mm) 吸附苯并 (a) 芘的能力。 (BaP) 和芘 (Pyr) 在 3 天和 30 天后的淡水中。BaP 比 Pyr 更容易被吸附，其中 PP 和 PS 分别是 BaP 最有效和最不有效的吸附剂。在混合溶液中，PAHs 吸附的差异比纯溶液更平滑，并且已观察到吸附的 PAHs 半衰期增加。同时，从淡水中分离出的细菌物种能够引起人类感染（大肠杆菌、肺炎克雷伯菌）和Aeromonas sobria）在塑料上组装生物膜进行了评估。生物膜组装随时间（1 至 3 个月）增加，可以观察 LDPE、HDPE 和 PS 上的生物膜。对于 PET 和 PP，仅在 3 个月后对原始 MP 的片段进行观察，才能观察到附着的细菌。 与未暴露的细菌相比，在 1 个月内暴露于 100 µg/mL PAHs（分离的或混合的）显着降低了细菌的持久性 ( p < .01)。