Speaker
Description
The intensive production and use of plastics in industry, medicine, and daily life have led to environmental pollution by various plastics. Fragmentation and degradation of plastic particles entering the environment result in the formation of microplastics (< 5 µm) and nanoplastics (< 1000 nm), which are not only smaller but also exhibit higher bioavailability, migration rates, and the ability to adsorb various pollutants, including metals and radionuclides. Nanoplastic particles carrying pollutants are more harmful because they can transport these substances in the environment and into living organisms. This research aimed to study the adsorption of Co²⁺ and Eu³⁺ on real-life nanoplastics (NPs) prepared from single-use plastic bottles and packaging materials by mechanical fragmentation and nanoprecipitation. Polystyrene (PS) and polyethylene terephthalate (PET) samples were characterised by SEM, TEM, and ATR-FTIR. Adsorption was studied in batch experiments using EuCl₃ and CoCl₂ solutions traced with ¹⁵²Eu and ⁶⁰Co, respectively. The activity concentrations of ⁶⁰Co and ¹⁵²Eu were measured by gamma spectrometry with HPGe detectors. The maximum adsorption efficiency for cobalt and europium on NPs ranged from 80% to 100%, depending on concentration, particle size, and experimental conditions. High efficiency for ⁶⁰Co and ¹⁵²Eu adsorption on the NPs was also observed in natural seawater. The experimental data were mostly in better agreement with the Langmuir isotherm model and the pseudo-second-order non-linear kinetic model. The data and modelling indicated a complex mechanism controlling the adsorption of ⁶⁰Co and ¹⁵²Eu on NPs. Adsorption on NPs was analysed using XPS, ATR-FTIR, and Raman spectroscopy. The results indicate a high adsorption potential of the NPs for ⁶⁰Co and ¹⁵²Eu and complex behaviour in the environment.
Acknowledgment: Research council of Lithuania - Student summer internship - Nr. P-SV3-25-500