Ultraviolet-C and vacuum ultraviolet inducing surface degradation of microplastics
| Autor: | Yuheng Chen, Huase Ou, Jialing Lin, Jianwei Fu, Deyi Yan |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Environmental Engineering
Vacuum Ultraviolet Rays Microplastics 0208 environmental biotechnology 02 engineering and technology 010501 environmental sciences Photochemistry medicine.disease_cause 01 natural sciences Water Purification chemistry.chemical_compound Adsorption X-ray photoelectron spectroscopy Polyethylene terephthalate medicine Irradiation Fourier transform infrared spectroscopy Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering Ecological Modeling Polyethylene Pollution 020801 environmental engineering chemistry Water treatment Plastics Water Pollutants Chemical Ultraviolet |
| Zdroj: | Water Research. 186:116360 |
| ISSN: | 0043-1354 |
| Popis: | Wastewater treatment plants (WWTPs) are considerable microplastics (MPs) contributors to environmental waters. Knowledge about the MPs degradation process under ultraviolet irradiation was crucial to understanding the fate of MPs during and after water disinfection. In this study, surface alternations of polystyrene (PS), polyethylene (PE), polyvinylchloride (PVC) and polyethylene terephthalate (PET) under 254 nm (UV-C) and 185/254 nm (vacuum ultraviolet, VUV) irradiation were estimated. One-way treatment of MPs by UV or VUV with the recommended dose for WWTPs (USEPA, ~180 mJ cm−2) had little effect. In contrast, excessive exposure under twenty-times doses irradiation (3600 mJ cm−2) resulted in significant alternations on surface morphology, chemical feature and hydrophobicity. Noticeably morphology alterations, including cracks, wrinkles and protuberances, were observed for PS, PVC and PET, while PE was relatively resistant. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that UV irradiation induced cleavage of chemical bonds. Besides, simultaneous radical oxidation was predominant during VUV treatment, which contributed to the increasing generation of oxygen bonds, such as C O and C O, on all MPs surfaces. Drastic decreases of contact angle (> 20°) were observed for PS, PVC and PET even after 180 mJ cm−2 UV irradiation, indicating the UV disinfection in WWTPs can easily change their surface hydrophobicity. All these alternations weakened the adsorption capacity of non-polar benzene and polar ciprofloxacin on MPs. Generally, regular dose UV and VUV irradiation in water treatment disinfection can only induce slight effects on MPs surface characteristics and adsorption performance, while extreme dose irradiation can induce a potential reducing risk of organic contaminants migration along with MPs. |
| Databáze: | OpenAIRE |
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