Impacts of microplastic decomposition using heat-activated persulfate on antibiotic adsorption and environmental toxicity

The objective of this study was to determine microplastic-antibiotic interaction by examining how heat-activated persulfate decomposed polyamide adsorbed antibiotics and explored the environmental consequences of treated water. Sulfate radicals roughened the microplastic surfaces, significantly enhancing the adsorption capacity of polyamide. The kinetic and isotherm studies provided confirmation that electrostatic interactions were the primary mechanisms, with a minor contribution from H-bonding, highlighting that antibiotic adsorption was prone to occur, especially on the aged surface. Thermodynamic data indicated that the process was spontaneous and exothermic. The results showed significant negative effects of treated water on seed germination, copepod survival, and cell lines at only a higher concentration, due to a decrease in pH and the potential presence of polymer degradates. Our findings revealed the significant impact of decomposed polyamide on the antibiotic adsorption and offered insight into the potential harm that microplastic-treated water might cause to aquatic and marine ecosystems.