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Povzetek: Plastics are polluting our environment and oceans with a large number and variety of organic and inorganic compounds that arise as a consequence of the current industrial development. Every year we release to the environment millions of tons of plastics whose total elimination may take centuries. The exponential increase in the production of this material is causing a serious environmental problem, resulting in the generation of a large amount of this waste. Microplastics (MPs) are released into the environment in different ways, but one of the most important is through effluents from wastewater treatment plants, since no specific method is used to eliminate or degrade these MPs before they are discharged into the environment. Polypropylene (PP), together with low-density polyethylene (PE), are the most common MPs found in the environment, being released in an amount of approximately 112 million tons per year. Three catalysts, ZnO/TiO2, CeO2/TiO2 and ZnO-CeO2/TiO2, were synthesized using the incipient wetness impregnation technique and tested under UV-A and UV-B irradiation for the degradation of polypropylene (PP) particles. A degradation of 6.6 ± 1.6 % of MP area in wastewater was obtained, slightly lower than the 8.4 ± 1.0 % observed with ultrapure water, likely due to the presence of organic matter and other compounds in the Waste Water Treatment Plant (WWTP) outlet. Additionally, toxicity assays using Phaeodactylum tricornutum revealed significant differences among treatments. The ZnO-CeO2/TiO2 catalyst resulted in lower growth inhibition compared to ZnO/TiO2, which showed toxicity levels similar to those of UV-aged PP-MPs without catalyst, highlighting the role of catalyst composition in modulating the environmental toxicity of degraded microplastics.
Ključne besede: wastewater, photocatalysis, advanced oxidation processes (AOPs), polymer degradation, environmental remediation
Objavljeno v DiRROS: 11.06.2026; Ogledov: 186; Prenosov: 216
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Povzetek: Cellulose acetate, commonly used in cigarette filters, poses environmental concerns due to its questionable (bio)degradability and prevalent presence in nature. This study compares the weathering effects on two types of cigarette filters: traditional and newer filters used in heated tobacco devices (HTP). Microplastics were derived from used cigarette parts and then subjected to artificial aging. Analytical techniques (Thermogravimetry-Differential Scanning Calorimetry TG/DSC, Fourier-Transform Infrared Spectroscopic Analysis (FTIR)) and loose bulk density measurements were employed pre- and post-aging cellulose acetate of both types of samples. Despite increasing evidence influencing European Union (EU) directives on tobacco product disposal, there's a lack of systematic analysis on the weathering impact, especially concerning the touted environmental benefits of newer filters. Results indicate decreased particle size in cellulose acetate filters post-aging. Variances were observed in thermal behavior, yet FTIR spectra remained unchanged.
Ključne besede: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Objavljeno v DiRROS: 12.03.2024; Ogledov: 3016; Prenosov: 1626
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Povzetek: Cellulose acetate is used in many applications, including for cigarette filters. Unfortunately, unlike cellulose, its (bio)degradability is under question, yet it often ends up uncontrolled in the natural environment. The main purpose of this study is to compare the effects of weathering on two types of cigarette filter (classic filters and newer filters that have more recently arrived on the market) following their use and disposal in nature. Microplastics were prepared from polymer parts of used (classic and heated tobacco products—HTP) cigarettes and artificially aged. TG/DTA, FTIR, and SEM analyses were performed both before and after the aging process. Newer tobacco products contain an additional film made of a poly(lactic acid) polymer which, like cellulose acetate, burdens the environment and poses a risk to the ecosystem. Numerous studies have been conducted on the disposal and recycling of cigarette butts and cigarette butt extracts, revealing alarming data that have also influenced the decisions of the EU, who addressed the disposal of tobacco products in the EU Directive (EU) 2019/904. Despite this, there is still no systematic analysis in the literature evaluating the impact of weathering (i.e., accelerated aging) on the degradation of cellulose acetate in classic cigarettes compared with that in newer tobacco products that have recently appeared on the market. This is of particular interest given that the latter have been promoted as being healthier and environmentally friendly. The results show that in cellulose acetate cigarette filters the particle size decreased after accelerated aging. Also, the thermal analysis revealed differences in the behavior of the aged samples, while the FTIR spectra showed no shifts in the position of the peaks. Organic substances break down under UV light, which can be seen by measuring the color change. The PLA film was found to be more stable than cellulose acetate under the influence of UV light.
Ključne besede: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Objavljeno v DiRROS: 30.06.2023; Ogledov: 2685; Prenosov: 1367
Celotno besedilo (5,78 MB)
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