Evaluation of microplastic contamination by metals in a controlled environment: A risk to be considered

Abstract

The metal contamination and the degradation of polyethylene terephthalate (PET) due to human activities have contributed to the worsening of environmental problems in aquatic systems. Therefore, the study aimed to evaluate PET microplastic adsorption levels when exposed to high amounts of Ni, Cu and Co. The PET microplastic was characterized by scanning electron microscopy, surface area, porosity, and Fourier transform infrared spectroscopy with attenuated total re ectance. The results showed that the surface area, the presence of macro and mesopores, and the functional groups in uence the adsorption of metals on the surface of PET microplastic. The construction and shape of the adsorption isotherms con rmed the presence of mesoporosity and macroporosity on the PET microplastic surface. The Freundlich and Langmuir models were used to study the adsorption capacity. The kinetics of adsorptions were interpreted using pseudo-rst order and pseudo-second order models. The results indicated that the Langmuir isotherm and the pseudo-second order adequately described the adsorption of metals by the PET microplastic. The removal rates by the PET microplastic varied from 8 to 34 % for Ni, 5 to 40 % for Cu and 7 to 27 % for Co after a period of 5 days. Furthermore, the adsorption was predominantly chemical and extremely fast, indicating that the presence of microplastics in the environment can lead to a rapid metal accumulation which elevates the hazards potential of microplastic in living beings. HighlightsA novel evaluation PET microplastic contamination by Ni, Cu and Co was reported Hazardous concentration of metals adsorbed on the PET surface was found from 5 daysThe adsorption process was well described by the Langmuir model