Abstract:
Microplastics are tiny plastic particles (less than 5 mm in size) that result from the breakdown of larger plastic materials or are intentionally manufactured for specific products. Their interaction with antibiotics raises concerns about environmental and human health risks. This study investigated the synthesis of micro-plastics and their adsorption of antibiotics. Nylon and polyethylene terephthalate (PET) from commercial sources were used to produce MPss. To simulate aging, MPss were oxidized via the Fenton reaction at 80°C in an acidic medium. Adsorption experiments, conducted using UV-visible spectroscopy, examined antibiotic retention on both aged and unaged MPss. Characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), digital microscopy, and scanning electron microscopy (SEM), were used to assess surface modifications. Results showed that aging increased doxycycline adsorption on nylon (Aged: 5.72 mg/g > Raw: 5.00 mg/g) and PET (Aged: 3.38 mg/g > Raw: 1.48 mg/g), likely due to surface changes. Cephalexin adsorption was higher on PET than nylon, with aging enhancing retention (Aged PET: 2.37 mg/g > Raw PET: 1.76 mg/g; Raw Nylon: 0.90 mg/g, Aged: 0.99 mg/g). Fulvic acid (FA) reduced doxycycline adsorption on raw nylon (2.90 mg/g vs. 5.00 mg/g) but increased it in aged nylon (6.98 mg/g vs. 5.72 mg/g), indicating variable effects. These findings highlight the formation of micro-plastic-antibiotic complexes and their potential environmental consequences. Understanding MPss’ antibiotic interactions is crucial for evaluating their long-term impact on ecosystems and public health.