Speaker
Description
Public concern about plastic pollution has led to rapid advances in detecting microplastics in environmental and biological samples. Currently, most research focuses on microplastics, while nanoplastics (NPs), which are more mobile in the environment and more harmful, have received less attention. Heavy metals and radionuclides adsorbed on colloidal-sized nanoparticles (< 1000 nm) can be transported over long distances in the environment and pose a threat to wildlife and humans.
This research aimed to study the adsorption kinetics of Co²⁺ and Eu³⁺ on real-life NPs, prepared from single-use plastic bottles and packaging materials by mechanical fragmentation and nanoprecipitation. Natural seawater and river water samples with a similar pH of 7.2 and varying salinity from 0 to 7 psu were used in the adsorption kinetics and desorption experiments. Adsorption was studied in batch experiments using solutions traced with 152Eu and 60Co, as well as polystyrene (PS) and polyethylene terephthalate (PET) samples. Particle sizes of PS and PET NPs ranged from 11 to 130 nm. The activity concentrations of 152Eu and 60Co were measured by gamma spectrometry with HPGe detectors. Nanoplastic samples were characterised using X-ray photoelectron spectroscopy (XPS), attenuated total reflectance infrared spectroscopy (ATR-FTIR), and Raman spectroscopy before and after adsorption. The kinetic adsorption data were more consistent with a pseudo-second-order non-linear kinetic model. Significant variations in desorption patterns were found depending on nanoparticle size and experimental conditions.