The potential of polyethylene microplastics to transport copper in aquatic systems: Adsorption and desorption studies.

Autor: Sathyamoorthy M; Chemical Engineering, HCT-Ruwais Woman's College, Ruwais, Abu Dhabi, United Arab Emirates., Senthilkumar R; Department of Engineering, University of Technology and Applied Sciences, Suhar, Sultanate of Oman., Saravanakumar K; Department of Engineering, University of Technology and Applied Sciences, Suhar, Sultanate of Oman., Reddy Prasad DM; Petroleum and Chemical Engineering Program, Faculty of Engineering, University of Teknologi, Brunei., Naveen Prasad BS; Department of Engineering, University of Technology and Applied Sciences, Salalah, Sultanate of Oman.
Jazyk: angličtina
Zdroj: Water environment research : a research publication of the Water Environment Federation [Water Environ Res] 2022 Nov; Vol. 94 (11), pp. e10809.
DOI: 10.1002/wer.10809
Abstrakt: Heavy metals and microplastics are two types of general contaminants that can cause significant damage to water systems and organisms. However, the interaction of heavy metal ions with microplastic in aquatic systems received less attention compared with that of organic contaminants. This study aims to explore the interaction of copper (II) ions with microplastic (polyethylene) in aquatic systems. The adsorption experiments were performed by varying several operational parameters including equilibrium pH, initial Cu (II) concentrations, and contact times. The microplastic was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared. The results confirmed the porous nature of the microplastic surface and the existence of various binding sites. The maximum Cu (II) uptake by microplastic was recorded as 1.23 mg/g at pH 5, according to the Langmuir adsorption isotherm. The experimental isotherm data exhibited a good fit to the Toth model, followed by the Langmuir and Freundlich equations, according to the correlation coefficient and %error values. The pseudo-first kinetics equation showed a better fit to copper (II) kinetics data compared with the pseudo-second kinetics equation. Elution of copper (II) ions from copper (II)-loaded microplastic was attempted using several elutants, and the results indicated that 0.01 M HNO 3 performed well with elution efficiency over 99.5%. Thus, the elution experiments furnished proof that Cu-loaded microplastic may leach Cu (II) ions under rich acidic conditions, thereby aiding the transport of Cu (II) ions into the digestive tracts of aquatic organisms. PRACTITIONER POINTS: Polyethylene microplastics showed potential to sorb copper ions. The mechanism was electrostatic interaction between microplastics and metal ions. Maximum copper adsorption by microplastic was recorded as 1.23 mg/g. Once desorbed, Cu(II) transferred into the digestive tracts of aquatic organisms.
(© 2022 Water Environment Federation.)
Databáze: MEDLINE
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