Mejías Carmen, Martín Julia, Martín-Pozo Laura, Santos Juan Luis, Aparicio Irene, Alonso Esteban
Departamento de Química Analítica, Escuela Politécnica Superior, Universidad de Sevilla, E-41011 Seville, Spain.
Antibiotics (Basel). 2024 Apr 29;13(5):408. doi: 10.3390/antibiotics13050408.
Microplastics (MPs) and antibiotics are emerging pollutants widely found in aquatic environments, potentially causing environmental harm. MPs may act as carriers for antibiotics, affecting their environmental distribution. This study investigates the adsorption of four macrolide antibiotics and a metabolite onto two types of MPs: polyethylene terephthalate (PET) and polyethylene (PE). Results revealed a linear isotherm adsorption model, with higher adsorption to PET than to PE ( > 0.936 for PE and > 0.910 for PET). Hydrophobic interactions and hydrogen bonding could be the main adsorption mechanisms, with pore filling potentially involved. Reduced particle size enhances adsorption due to the increase of active adsorption sites. This increasement is more pronounced in PE than in PET, leading to an 11.6% increase in the average adsorption of all macrolides to PE, compared to only 5.1% to PET. Dissolved organic matter inhibits adsorption (azithromycin adsorption to PE was reduced from 12% to 5.1%), while salinity enhances it just until 1% salinity. pH slightly influences adsorption, with maximal adsorption at neutral pH. Results in real samples showed that complexity of the matrix decreased adsorption. Overall, these findings indicate that PE and PET MPs can be a vector of macrolides in aquatic environments.
微塑料（MPs）和抗生素是在水生环境中广泛发现的新兴污染物，可能对环境造成危害。微塑料可能充当抗生素的载体，影响其在环境中的分布。本研究调查了四种大环内酯类抗生素及其一种代谢物在两种微塑料上的吸附情况，这两种微塑料分别是聚对苯二甲酸乙二酯（PET）和聚乙烯（PE）。结果显示为线性等温吸附模型，PET对其吸附能力高于PE（PE的吸附系数>0.936，PET的吸附系数>0.910）。疏水相互作用和氢键可能是主要的吸附机制，可能还涉及孔隙填充。粒径减小会因活性吸附位点增加而增强吸附作用。这种增加在PE中比在PET中更明显，与PET中所有大环内酯类抗生素平均吸附量仅增加5.1%相比，PE中所有大环内酯类抗生素平均吸附量增加了11.6%。溶解有机物会抑制吸附作用（阿奇霉素在PE上的吸附量从12%降至5.1%），而盐度在达到1%之前会增强吸附作用。pH对吸附作用影响较小，在中性pH条件下吸附量最大。实际样品的结果表明，基质的复杂性会降低吸附作用。总体而言，这些研究结果表明，PE和PET微塑料可能是水生环境中大环内酯类抗生素的载体。
