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On the road to understand the toxicity of nanoplastics, it is important to determine their capacity to interact with other molecules, as this is the first condition that must be met. In particular, polyvinyl chloride (PVC) is a versatile plastic widely used in construction. It can be degraded producing micro and nanoplastics, which can be formed when PVC pipes are cut during the manufacturing of products. PVC is considered to be one of the most toxic plastics, so it is important to analyze potential detrimental effects. This is the main aim of this research. On the basis of Density Functional Theory calculations, we investigated different vinyl chloride oligomers (as models of PVC nanoplastics). Degradation energies, electron donor acceptor capacities to analyze possible oxidation reactions, and interaction energies with different molecules were calculated. The vinyl chloride oligomers used in this investigation are saturated and monounsaturated. This is important since monounsaturated variant is dominant in experimental conditions. We found that none of the oligomers are good electron donors or acceptors. We also investigated different oligomers interacting with ciprofloxacin and •OOH. The interaction energies with ciprofloxacin and •OOH are negative or less than 13 kcal/mol, indicating weak interactions. This theoretical investigation indicates that vinyl chloride oligomers are not expected to be reactive or toxic, considering the electron transfer and the interaction energies with other molecules.

In this study, we developed a novel nanocomposite-based membrane using maghemite copper oxide (MC) to enhance the separation efficiency of poly(vinyl chloride) (PVC) membranes for oil-in-water emulsions. The MC nanocomposite was synthesized using a co-precipitation method and incorporated into a PVC matrix by casting. The resulting nanocomposite-based membrane demonstrated a high degree of crystallinity and well-dispersed nanostructure, as confirmed by TEM, SEM, XRD, and FT-IR analyses. The performance of the membrane was evaluated in terms of water flux, solute rejection, and anti-fouling properties. The pinnacle of performance was unequivocally reached with a solution dosage of 50 mL, a solution concentration of 100 mg L −1 , and a pump pressure of 2 bar, ensuring that every facet of the membrane’s potential was fully harnessed. The new fabricated membrane exhibited superior efficiency for oil–water separation, with a rejection rate of 98% and an ultra-high flux of 0.102 L/m 2  h compared to pure PVC membranes with about 90% rejection rate and an ultra-high flux of 0.085 L/m 2  h. Furthermore, meticulous contact angle measurements revealed that the PMC nanocomposite membrane exhibited markedly lower contact angles (65° with water, 50° with ethanol, and 25° with hexane) compared to PVC membranes. This substantial reduction, transitioning from 85 to 65° with water, 65 to 50° with ethanol, and 45 to 25° with hexane for pure PVC membranes, underscores the profound enhancement in hydrophilicity attributed to the heightened nanoparticle content. Importantly, the rejection efficiency remained stable over five cycles, indicating excellent anti-fouling and cycling stability. The results highlight the potential of the maghemite copper oxide nanocomposite-based PVC membrane as a promising material for effective oil-in-water emulsion separation. This development opens up new possibilities for more flexible, durable, and anti-fouling membranes, making them ideal candidates for potential applications in separation technology. The presented findings provide valuable information for the advancement of membrane technology and its utilization in various industries, addressing the pressing challenge of oil-induced water pollution and promoting environmental sustainability. Graphical Abstract

A large amount of graphene-related research is its use as a filler for polymer composites, including thin nanocomposite films. However, its use is limited by the need for large-scale methods to obtain high–quality filler, as well as its poor dispersion in the polymer matrix. This work presents polymer thin-film composites based on poly(vinyl chloride) (PVC) and graphene, whose surfaces were modified by curcuminoids. TGA, UV–vis, Raman spectroscopy, XPS, TEM, and SEM methods have confirmed the effectiveness of the graphene modification due to π–π interactions. The dispersion of graphene in the PVC solution was investigated by the turbidimetric method. SEM, AFM, and Raman spectroscopy methods evaluated the thin-film composite’s structure. The research showed significant improvements in terms of graphene’s dispersion (in solutions and PVC composites) following the application of curcuminoids. The best results were obtained for materials modified with compounds obtained from the extraction of the rhizome of Curcuma longa L. Modification of the graphene’s surface with these compounds also increased the thermal and chemical stability of PVC/graphene nanocomposites.

Microplastics (MPs) are considered as contaminants of emerging concern to the environment and our food chains in recent years. In this study, we presented a multi-technique-based analytical method for detection of MPs through a combination of microscope-FTIR (μ-FTIR) with pyrolysis-GC/MS (Py-GC/MS) to achieve 3-dimensional (3D) information for the identification of polymer type, characterization of particle size and morphology, and quantification of MPs based on both particle number and mass of plastics. Plastics that are commonly used and disposed of, including polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), poly vinyl chloride (PVC), polyamide (PA), and poly(methyl methacrylate) (PMMA), were covered in this study. Sample extraction and separation procedures were optimized for these microplastics in table salts where good recoveries (> 75%) were achieved. To further enhance the detection sensitivity in simultaneous quantification of multiple polymers in a sample, a serial dissolution approach with different solvents was developed for the detection of all 7 types of plastics. The established sample preparation process and multi-technique-based analytical method were validated with polymer standards in table salts, resulting in satisfactory qualification and quantification for all samples tested. A retail survey of MPs in table salts was conducted with the developed analytical method, revealing that MPs were present in all commercially available table salts. The total number of MP particles varied from 20 to 125 particles/kg and the total mass contents of seven types of plastics ranged from 30 to 530 µg/kg in table salts.

The amounts of microplastics in sediment samples obtained from four stations along the Jeddah coast were shown to range from not detected to 119?particles?kg?1 wet sediment. Four classes of microplastic particles in the sediment, that is, fragments, granules, foams and fibres, were characterised by fluorescence microscopy. Microplastics of various forms and sizes were also identified in 44?% of the 140 sampled fish (6 local species) in amounts ranging from not detected to 30 microplastic particles per individual. Polyethylene terephthalate and vinyl chloride-vinyl acetate copolymers were the dominant polymer types in the sediment samples identified by Fourier-transform infrared spectroscopy (FTIR) analysis, while polystyrene, polyethylene and polyester were the dominant polymer types detected in fish. FTIR analysis showed that the most detected fibres were made of polyester. The results of this study emphasise that microplastic pollution represents an emerging threat to the marine environment of the Red Sea. The results of this study provide useful background information for further investigations and provide an accurate overview of the microplastics distribution in the marine environment of the Saudi Red Sea.

The paper presents the characteristics of unplasticized PVC composites modified with biofiller obtained from the waste eggshells of hen eggs. The composites obtained by extrusion contained from 10 phr to 40 phr of biofiller. The filler was characterized using the SEM, TG, and sieve analysis methods. The influence of the filler on the processing properties was determined using plastographometric and MFR tests. Fundamental analysis of mechanical properties was also performed, i.e., Charpy impact strength and determination of tensile properties. The mechanical properties were supported with dynamical mechanical thermal analysis, time of thermal stability, and thermogravimetric analysis. Structure analysis was also performed using SEM and X-ray microcomputed tomography (micro-CT). The processing properties of the tested composites do not give grounds for disqualifying such material from traditional processing PVC mixtures. Notably, the biofiller significantly improves thermal stability. Ground eggshells (ES) work as scavengers for the Cl radicals released in the first stage, which delays the PVC chain’s decay. Additionally, a significant increase in the value of the modulus of elasticity and softening point (VST) of the composites concerning PVC was found. Ground hen eggshells can be used as an effective filler for PVC composites.

In this work, a method to increase the dispersion of graphene (GN) in the matrix of rigid poly(vinyl chloride) (PVC) by using a natural plant extract from Curcuma longa L. (CE) is proposed. Currently, despite the increasing number of reports on the improvement of GN dispersion in PVC blends, still there is a need to find environmentally friendly and economical dispersion stabilizers. We proposed a stabilizer that can be easily obtained from a plant offering thermal stability and high effectiveness. PVC/GN nanocomposites stabilized with the proposed extract were investigated by SEM, AFM (structure), TGA, and Congo red test (thermal properties). Additionally, static and dynamic mechanical properties and electrical resistivity were measured. The use of CE as a graphene dispersant improved its dispersion in the PVC matrix, influenced tensile properties, increased the storage modulus and glass transition temperature, and extended the thermal stability time of nanocomposites. In this work, a CE extract is proposed as an efficient eco-friendly additive for the production of nanocomposites with an improved homogeneity of a nanofiller in the matrix and promising characteristics.

Microplastic pollution in soil poses a growing environmental threat with far-reaching implications for ecosystems and human health. This study systematically investigated the distribution of microplastics (MPs) across various soil depths in diverse mulched agricultural fields. Soil samples were meticulously collected at three depths (0–5, 5–10, and 10–15 cm) from five distinct agricultural regions in Bangladesh. The analysis of MPs was conducted using Fourier Transform Infrared Spectroscopy (FTIR) and a fluorescent microscope. Notably, the results unveiled no discernible depth-related trends in MP concentration, displaying ranges of 0.13 ± 0.35 to 3.53 ± 1.77; 0 to 5.53 ± 2.36; and 0 to 4.07 ± 2.28 MPs/g of soil in 0–5 cm, 5–10 cm, and 10–15 cm, respectively. The soil exhibited a spectrum of microplastic types, including High-Density Polyethylene (HDPE), Polyethylene terephthalate (PET), Polypropylene (PP), Low-Density Polyethylene (LDPE), Poly Vinyl chloride (PVC), Poly Vinyl Alcohol (PVA), Poly vinyl fluoride (PVF), and Polytetrafluoroethylene (PTFE), ranging from 0.04 ± 0.21–3.71 ± 2.36 MPs/g of soil. Particularly, the industrial agricultural area displayed the highest microplastic concentration (12.89/g of soil). Further, Principal Component Analysis identified plastic mulch and organic manure as potential sources. Despite the presence of microplastic, the estimated concentrations indicated low risks to the farming community in Bangladesh. This research provides valuable insights into microplastic distribution in agricultural soils, enhancing our understanding of this form of pollution.

Volatile organic compounds (VOCs) typically exist in the aqueous environment due to global anthropogenic activities. The distribution and contaminated profile (or characteristics) of VOCs in the groundwater of Lanzhou, China, were investigated in this study. Groundwater samples were collected from 30 sampling points in December 2015, and a total of 17 VOCs were analyzed by purge and trap gas chromatography–mass spectrometry. Thirteen types of VOCs were detected at 29 sampling points in the study area. Of these, dichloromethane and toluene, which were found at 22 sampling points, had the highest detection frequency (73.3%), followed by benzene (66.7%), 1,2-dichloroethane (50%), and xylenes (50%). The highest average concentration among the detected VOCs was found for chloroform (5151.5 μg/L). The spatial distribution of VOC contamination in four major urban areas of Lanzhou and the variation in VOC concentration caused by land use transitions were also analyzed. The results showed that Xigu district was the most polluted area in Lanzhou, mainly due to land use for industrial proposes. On the contrary, the samples for Anning district showed lower VOC concentrations because of better groundwater quality, which is associated with the absence of manufacturing industries in this region. The health risk assessment model developed by the United States Environmental Protection Agency was employed in this study to evaluate safety for drinking water use. This study found that despite considering the volatilization of VOCs from water due to heating, six sampling points (G05 in Qilihe district; G07 and G09 in Xigu district; G16, G17, and G15 in Chengguan district) showed non-carcinogenic risks, ranging from 1.63 to 14.2, while three points (G16 in Chengguan district, and G10 and G07 in Xigu district) exhibited high carcinogenic risks for human health, ranging from 2.94 × 10−4 to 6.85 × 10−4. Trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene were identified as the dominant VOCs, presenting high non-carcinogenic risk. 1,2-dichloroethane and vinyl chloride were the primary factors for high carcinogenic risk. The high-risk areas were concentrated in Xigu and Chengguan districts, suggesting the need to alert the relevant local government departments.

ObjectiveTo evaluate mortality risks of angiosarcoma of the liver (ASL), primary hepatocellular carcinoma (HCC) and other cancers among 9951 men employed between 1942 and 1972 at 35 US vinyl chloride (VC) or polyvinyl chloride plants followed for mortality through 31 December 2013.MethodsSMR and time-dependent Cox proportional hazards analyses were used to evaluate mortality risks by cumulative VC exposure.ResultsLiver cancer mortality was elevated (SMR=2.87, 95% CI 2.40 to 3.40), and ASL and HCC were strongly associated with cumulative VC exposure ≥865 parts per million-years (ppm-years) (ASL: HR=36.3, 95% CI 13.1 to 100.5; and HCC: HR=5.3, 95% CI 1.6 to 17.7 for ≥2271 ppm-years). Excess deaths due to connective and soft tissue cancers (SMR=2.43, 95% CI 1.48 to 3.75), mesothelioma (SMR=2.29, 95% CI 1.18 to 4.00) and explosions (SMR=3.43, 95% CI 1.25 to 7.47) were seen. Mortalities due to melanoma, brain cancer, lung cancer and non-Hodgkin’s lymphoma were not increased or associated with VC exposure.ConclusionThe association between VC and ASL first reported in this cohort 44 years ago persisted and was strongest among workers most highly exposed. VC exposure also was associated with HCC mortality, although it remains possible that misdiagnosis of early ASLs influenced findings.