Search Results (586)

Biomass, composed of natural polymers such as cellulose, hemicellulose, and lignin, can be converted into circular chemical feedstocks through thermochemical conversion processes like pyrolysis. Char conversion is the rate-limiting step in the thermochemical conversion process, and thus, char reactivity is essential for determining the overall efficiency of pellet-based thermochemical processes. Pyrolysis experiments were conducted on rice straw pellets of different sizes (i.e., 8, 10, and 12 mm) in a vertical quartz tube reactor at 700 °C, and then the chemical structure of chars sampled at different stages and locations within a 10 mm pellet was analyzed using Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The results indicate that increasing the pellet size facilitates the growth of polycyclic aromatic structures, as evidenced by the observed variations in the abundance of typical aromatic compounds in bio-oil. This also promotes volatile–char interactions, leading to greater deposition of large aromatic structures on the char surface, thereby enhancing char aromatization. Analogous to the spatial scale effect of pellet size on char structure, the evolution of the char structure within a single pellet exhibits distinct spatial heterogeneity during the initial devolatilization and subsequent char aromatization stages due to the location-dependent coupling of heat/mass transfer limitations and aromatization reactions during pyrolysis. Furthermore, the spatiotemporal evolution of the char structure leads to differences in the specific reactivity: during the devolatilization stage at 75 s, the center exhibits the highest reactivity, whereas the outer surface becomes the most reactive in the subsequent char aromatization stage at 300 s. Full article

Atmospheric particulate matter poses a high risk by carrying potentially toxic components such as polycyclic aromatic hydrocarbons (PAHs). The major sources of these potentially toxic compounds include traffic-related emissions and winter heating, implying the combustion of fossil fuels or biomass. Air pollution, especially chronic exposure, poses the most serious human health hazard in childhood, and several studies emphasise the importance of research on the potential impacts of air pollution in school environments. While indoor air quality studies are already available in Hungary, investigations on outdoor air pollution in school environments are missing. To fill this gap, in a medium-sized Hungarian town, Veszprém, six schools were selected to assess air quality in the outdoor environments where schoolchildren spend their breaks and have physical training. These schools represent different locations and conditions, from high-trafficked sites to suburban environments. Using resuspended dust samples, environmental quality was assessed based on PAH contents of the samples and ecotoxicity tests (Vibrio fischeri bacterial bioassay). Ecotoxicity of the samples moved in a wide range, from highly toxic to non-toxic. PAH measurements indicated considerable contamination in the case of one sample taken from a suburban area. Source apportionment demonstrated that winter heating is also an important pollution source. Full article

Pyrolysis of refuse-derived fuel (RDF) is a promising waste-to-energy route, but its use in higher-value applications remains limited by tar carryover, benzene, toluene, ethylbenzene, and xylenes (BTEX), heteroatom-containing compounds, and pollutant accumulation in recirculated scrubber water. This study evaluated operating windows for RDF pyrolysis coupled with direct wet scrubbing and closed-loop water reuse, with the aim of identifying regimes suitable for different end-use tiers. A Taguchi L27 design of experiments (DOE), i.e., an orthogonal array comprising 27 experimental runs, was applied to evaluate the effects of pyrolysis temperature, residence time, scrubber liquid-to-gas ratio, and scrubber-water temperature, while sequential reuse of the same scrubber-water inventory was evaluated at 5, 10, and 15 cycles. Cleaned-gas pollutants were quantified by compound-resolved gas chromatography–mass spectrometry (GC–MS) after solid-phase adsorption (SPA) sampling, while phenolics and polycyclic aromatic hydrocarbons (PAHs) in scrubber water were determined by extraction followed by GC–MS. Feasibility within each end-use tier was defined as simultaneous satisfaction of tier-specific cleaned-gas thresholds (C_tar, C_BTEX, I_N, and I_S) and the corresponding water-loop hazard limit (I_tox), using literature-informed engineering screening criteria. The results showed that stronger scrubbing reduced gas-phase tar and BTEX burdens, whereas extended water reuse caused systematic accumulation of phenolics and PAHs and increased the composite water-loop hazard index. Boiler-grade operation remained feasible across a broad operating range, with 23 of the 27 tested conditions remaining robust, whereas internal combustion engine combined heat and power (ICE-CHP) feasibility was restricted to a narrow robust regime, and no robust microturbine-grade condition was identified. These findings show that operating windows for RDF pyrolysis must be defined jointly by gas cleanliness and water-loop management constraints. Full article

Unpolluted water, both freshwater and saltwater, is essential for achieving several United Nations Sustainable Development Goals, particularly SDGs 6, 3, 2, 14, and 15. This study maps emerging water-quality monitoring technologies at intermediate technological readiness levels (TRLs 4–5) and their potential patent markets (TRL 9). A total of 40,469 patent families were retrieved from the Espacenet worldwide database using IPC G01N33/18 and used to analyze sensing parameters. A subset of 2146 water-pollution-related patents was analyzed in detail. The analysis covered sensing parameters, temporal trends, compound annual growth rates (CAGR), legal status, geographic distribution of patent origins and markets, and the technological landscape, including application domains and niche clusters. The results show pronounced exponential growth in patent filings since 2014 and a high share of active documents, indicating sustained global investment. Innovation leadership is concentrated in China, South Korea, India, the United States, and Japan, with export-oriented patents largely held by transnational corporations, while African participation remains limited. Technological trends prioritize multiparameter environmental and biological sensing, addressing pH, temperature, turbidity, dissolved oxygen, nutrients, heavy metals, polycyclic aromatic hydrocarbons (PAHs), and oxidation–reduction potential. Emerging solutions integrate autonomous platforms, remote sensing, Internet-of-Things architectures, and machine-learning-based analytics. Persistent bottlenecks include sensor robustness in harsh aquatic environments and the reliable discrimination between background variability and early pollution signals. Strengthening low-cost and scalable deployment remains essential to ensure water quality, support environmental sustainability, and minimize risks. Full article

This work investigates the physicochemical characteristics of waste tire pyrolysis char (WTP-char) produced at 500 °C in an industrial-scale auger reactor. The study uniquely combines material profiling with environmental safety assessment, specifically targeting organic contaminants and polymer stabilizers, evaluating WTP-char’s potential for circular economy applications. The samples underwent comprehensive analysis, including GC-MS, TGA, SEM-EDS, TXRF, and BET surface area measurements. The results revealed a high volatile matter content (13 wt.%), attributed to the thermal inertia typical of industrial-scale units. The organic fraction was dominated by n-alkanes (48.3%) and a significant concentration (6.97%) of the stabilizer Tris(2,4-di-tert-butylphenyl) phosphate (bDtBPP), posing potential environmental risks due to its cytotoxicity. Polycyclic aromatic hydrocarbon (PAH) analysis showed a prevalence of high-molecular-weight (HMW) compounds (79.7%), indicating high chemical stability. Although the specific surface area was low (28.9 m²/g), suggesting the need for activation, the material exhibits potential as a low-cost semi-reinforcing filler or solid fuel. By moving beyond laboratory-scale experiments to real industrial production, this study establishes a practical framework for evaluating both the performance and environmental safety of waste tire pyrolysis char. Full article

The Black Sea is highly vulnerable to environmental degradation, making the evaluation of contaminant transfer within its food webs essential for ecosystem protection, sustainable resource management, and human health risk assessment. Marine organisms accumulate contaminants through three main processes: bioconcentration (direct uptake from the abiotic environment), biomagnification (trophic transfer through consumption of contaminated prey), and bioaccumulation, which integrates contaminants from all exposure pathways. Despite numerous studies reporting contaminant concentrations in Black Sea waters, sediments, and biota, integrated analyses of trophic transfer within both pelagic and benthic food webs in the Romanian coastal sector remain limited. This study assessed the bioamplification of heavy metals—HMs, persistent organic pollutants—POPs (OCPs, PCBs) and polycyclic aromatic hydrocarbons—PAHs along the main pelagic and benthic food webs in the Romanian coastal sector, based on concentrations measured in representative invertebrate and fish species. The results revealed a compartment-driven contamination pattern, with the benthic food web functioning as an important reservoir and transfer pathway. Heavy metals showed variable and context-dependent trophic transfer, with selective amplification for Cu and Ni in some benthic links, trophic dilution or neutral transfer for Cd and Pb, and more consistent retention for Cr. In contrast, several PCB congeners showed clear biomagnification, particularly in benthic predator–prey relationships. PAHs displayed compound-dependent trophic transfer, with more pronounced amplification in benthic pathways. Overall, biomagnification was stronger for organic pollutants, particularly PCBs, than for heavy metals. The study contributes to two United Nations Sustainable Development Goals (SDGs): SDG 14 (Life Below Water) and SDG 12 (Responsible Consumption and Production). Full article

Bioturbating animals move around large amounts of sediment, changing its physicochemical properties and biogeochemical processes. The present study assessed the role of the ghost shrimp Lepidophthalmus louisianensis, a major coastal bioturbator in the Northern Gulf of Mexico, in the fate of crude oil after the 2010 Deepwater Horizon blowout. Experiments were conducted in greenhouse mesocosms, with or without ghost shrimp and with or without added oil, reflecting mild surface or subsurface oiling in a beach environment. To evaluate the hydrocarbon-degradation potential of the sediment microbial community, a respirometric radiotracer assay was conducted with ¹⁴C naphthalene as a model polycyclic aromatic hydrocarbon (PAH) compound. Oil augmentation led to a substantial increase in the PAH degradation potential of mesocosm sediments, which was further enhanced by the presence of the bioturbator. However, bioturbation alone, without previous oil exposure, did not enhance naphthalene degradation. 16S rRNA gene analyses showed that there were no significant changes in the microbial community composition associated with either bioturbation, oil augmentation, or both. This study demonstrated bioturbation- and oil-exposure-related enhancement in hydrocarbon degradation in mildly oiled sediment, and indicated that this may be due to an increased expression of PAH degrading activities in the preexisting community of hydrocarbon-degrading bacteria rather than resulting from a shift in the microbial community composition. Full article

The occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), fragrances, UV filters and photoinitiators were investigated in surface sediments of Nerbioi-Ibaizabal estuary between 2005 and 2013, in 2020. Samples were extracted by focused ultrasound solid–liquid extraction technique and analyzed by gas chromatography coupled with mass spectrometry. Total PAHs, PCBs, OCPs, musks, UV filters and photoinitiators concentrations ranged between not detected (n.d.) and 43000 ng g⁻¹, n.d. and 2500 ng g⁻¹, n.d. and 820 ng g⁻¹, n.d. and 880 ng g⁻¹, n.d. and 91 ng g⁻¹ and from nd to 120 ng g⁻¹, respectively. Hexachlorocyclohexanes (HCHs) were ubiquitous in the estuary, suggesting that these compounds, although banned, leach from landfills. The PCB concentrations showed a decreasing trend. Ecological risk assessments based on sediment quality guidelines (SQGs) and risk quotient (RQ) suggested semi-volatile organic compounds could represent a potential ecological risk in the Nerbioi-Ibaizabal estuary. Full article

Human skin and hair act as multifunctional barriers but are highly sensitive to environmental pollutants originating from air, water, and cosmetic products. Epidemiological studies report that exposure to particulate matter (PM_2.5–PM₁₀), nitrogen oxides (NO_x), and volatile organic compounds increases the risk of skin and hair disorders. For instance, women in high-traffic areas (N = 211) show significantly more pigment spots and nasolabial wrinkles compared to those in rural areas (N = 189), indicating accelerated skin ageing. Children aged 9–11 exposed to PM₁₀, benzene, and NO_x exhibit increased incidence of atopic dermatitis. Systemic exposure to dioxins causes chloracne, while co-exposure to polycyclic aromatic hydrocarbons (PAHs) and UVA radiation elevates skin cancer risk. Psoriasis flares are associated with mean pollutant concentrations over the 60 days preceding flare events in 957 patients, and hyperpigmentation prevalence increases in populations exposed to traffic-related PM and ROS-inducing pollutants. Hair loss is linked to oxidative stress from PM and PAHs absorbed on hair fibers, with in vitro studies showing keratinocyte apoptosis in scalp hair follicles. This review evaluates natural adsorbents such as zeolites, clays, activated carbon, and polyphenol-rich plant extracts for anti-pollution cosmetic formulations. Adsorption capacities range from 60 to 150 mg·g⁻¹ depending on the pollutant, with removal efficiencies of 30–55% in model topical systems. Mechanisms include ion exchange, surface adsorption, hydrophobic interactions, and radical scavenging. Incorporating 2–5% w/w of these adsorbents in cosmetic formulations significantly reduces pollutant deposition on skin and hair. These findings support the development of evidence-based, sustainable anti-pollution cosmetic strategies that quantitatively mitigate environmental stressor effects. Full article

The complex contamination characteristics and potential health risks of polycyclic aromatic hydrocarbons (PAHs) and their derivatives remain poorly understood. In this study, a comprehensive analysis of 16 parent PAHs and 34 derivatives was conducted in outdoor dust samples collected from a residential area constructed on an abandoned petrochemical site. The results showed that the total concentrations of PAHs, oxidized PAHs, nitro-PAHs, brominated PAHs, and chlorinated PAHs were in the ranges of 75.3–991 ng/g, 9.27–142 ng/g, 1.68–265 ng/g, 15.2–100 ng/g, and 1.23–14.8 ng/g, respectively. Additionally, the non-target screening analysis identified 29 potential aromatic compounds in dust samples. Toxicity assessment indicated that several PAH derivatives and newly identified compounds exhibited stronger acute toxicity than PAHs (ECOSAR model prediction). Incremental lifetime cancer risk (ILCR) values of target compounds ranged from 1.54 × 10⁻⁷ to 2.95 × 10⁻⁶ for adults and from 5.08 × 10⁻⁸ to 9.75 × 10⁻⁷ for children. Oral ingestion was identified as the dominant exposure pathway, accounting for 83.5% of total exposure, followed by dermal contact (16.5%). Overall, these findings highlight the complexity of human exposure to PAHs and related aromatic contaminants in petrochemical-impacted residential areas and underscore the need for continued attention to their associated environmental and health risks. Full article

Breast cancer is the most common malignant tumor among women worldwide, and its occurrence is closely associated with long-term exposure to environmental pollutants. Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants widely present in the living environment. Epidemiological studies indicate that exposure to PAHs increases the risk of breast cancer. PAH derivatives exhibit stronger toxicity or endocrine-disrupting activity than their parent compounds; however, research on their specific effects and mechanisms in breast cancer cells remains limited. For this purpose, this study selected 3-Hydroxybenz[a]anthracene, a PAH derivative with potential estrogenic activity, as the target compound. Using the estrogen receptor-positive breast cancer cell line MCF-7 as the model, we performed EdU staining, colony formation assays, scratch healing assays, Transwell invasion assays, and apoptosis assays and preliminarily examined changes in relevant signaling proteins via Western blot. Results indicate that 3-Hydroxybenz[a]anthracene promotes proliferation and migration in MCF-7 cells while inhibiting apoptosis under certain conditions, but it has no effect on cell invasion. Mechanistically, it upregulates key proteins including AKT, c-Myc, E-Cadherin, Vimentin, MMP2, MMP9 and Bcl-2 while downregulating p-AKT expression. This study confirms through in vitro experiments that 3-Hydroxybenz[a]anthracene exhibits estrogen-like effects and modulates malignant behavior in breast cancer cells by regulating relevant signaling pathways. These findings provide experimental evidence for further evaluating the potential role of this environmental contaminant in breast cancer initiation and progression. Full article

Cellular senescence (CSEN) is caused by a variety of factors that trigger complex molecular pathways. These include telomere shortening, oncogene activation and replicative stress, as well as DNA damage caused by genotoxic anticancer drugs and endogenous and exogenous genotoxins. Here, we review the induction of CSEN by exogenous genotoxic insults resulting from food and environmental exposures. The available data show that genotoxins/carcinogens in tobacco smoke and smokeless tobacco, in the environment, in food, beverages and life-style products induce CNS. The exposures include N-nitroso compounds, polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, acrylamide, heavy metals, fine dust, mycotoxins, phytotoxins, and phycotoxins. Also, heme in red meat contributes to CSEN as it catalyzes the formation of genotoxic species in the colon. Induction of CSEN by external genotoxins/carcinogens is bound on the DNA damage response pathway (DDR), which relies on activation of the ATM/ATR-CHK2/CHK1-p53-p21 axis and the p53-independent p16/p14 axis, eliciting cyclin-dependent kinase inhibition and permanent cell cycle arrest. Other factors that can be involved are DREAM, MAPK, cGAS/Sting, and NF-κB. The accumulation of non-repaired DNA damage triggering CSEN following external genotoxic exposures may contribute significantly to the amelioration of senescent cells and organ failure with age in humans. Senescent cells drive, via the senescence-associated secretory phenotype (SASP), inflammation that is involved in many diseases, including cancer. Although most of the studies were performed with in vitro cell systems, the consequences of CSEN induction by genotoxic nutritional components and environmental exposures seem to be underestimated. Since CSEN correlates with aging, it is reasonable to conclude that exogenous genotoxic pollutants contribute significantly to the aging process through CSEN induction. In light of these findings, it is deduced that reducing genotoxin exposures and using “rejuvenation” supplements (senotherapeutics) are reasonable strategies to counteract cellular senescence and the aging process. Full article

This investigation was conducted in order to gain a first knowledge of concentrations, distribution patterns, and potential sources of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and organic molecular tracer compounds in deposition dust samples collected in the Valparaiso region, Chile. Dust was sampled in schools (indoor and outdoor) that are located in Puchuncaví and Quintero. Source apportionment analysis using the concentrations of PAHs; glucose, mannitol, sucrose, fructose; di-2-ethylhexyl phthalate; hopanes, and levoglucosan as molecular tracer compounds showed three sources of contribution. The first (46.38%) was related to incomplete combustion processes (Acy, Flu, Ant, Flt, Pyr, and BaA), a second source (20%) represented soil+ biomass burning (levoglucosan, α glucose, β glucose, mannitol, sucrose, and fructose), and a third source (10.26%) was dominated only by 27_norhopane, 27_hopane, which are related to traffic. To assess potential health risks for schoolchildren, the study calculated the benzo[a]pyrene equivalent (BaPE) toxicity and the incremental lifetime cancer risk (ILCR). Toxicity equivalent (TEQ) results showed that the main contributor to overall toxicity in PAHs, especially in schools located in Puchuncaví, was benzo[a]pyrene (BaP), followed by benzo[α]anthracene (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd] pyrene (IcdP), and dibenzo[a,h]anthracene (DahA). According to the calculated ILCR values, the highest cancer risk was associated with dust ingestion (both indoor and outdoor) for ∑16PAHs, ranging from 1.14 × 10⁻³ to 8.88 × 10⁻⁴. This was followed by dermal contact (1.27 × 10⁻⁵ to 7.27 × 10⁻⁷) and inhalation (1.22 × 10⁻⁸ to 9.99 × 10⁻⁹). Full article

Owing to their small size and surface hydrophobicity, microplastics (MPs) tend to act as vectors for various organic pollutants. However, in contrast to well-studied pollutants like polycyclic aromatic hydrocarbons, the sorption of benzene-series compounds on MPs has been seldom studied. To investigate the sorption process, the isotherms were determined for the sorption of three benzene-series sorbates by three polymers with different physicochemical properties. The linear sorption isotherms observed for PE indicate that sorbate uptake was dominated by partitioning into the bulk polymer. In contrast, the non-linear isotherms of PP and PVC imply that adsorption onto surfaces was the dominant mechanism. Sorption capacity of m-xylene and ethylbenzene increased in the following order: polyvinyl chloride (PVC) < polyethylene (PE) < polypropylene (PP). This order does not reflect the polarity or the crystallinity of the investigated MPs, suggesting the influence of additional factors (e.g., glass transition temperature, specific surface area) on the sorption of BTEX by MPs. In addition, the particle size and morphology of MPs are also factors affecting sorption capacity. The strong correlation between the sorption coefficients and sorbate hydrophobicity indicates that the hydrophobic interactions played a crucial role. Meanwhile, specific sorbate properties, such as electronic structure and molecular polarizability, are also significant factors that affect the sorption behaviors. Full article

Cellulose has received significant attention, given its high demand for the transition to sustainable fuels and renewable energy, addressing the environmental challenges of fossil fuels. Fast pyrolysis is a process that can transform cellulose into bio-oil. Although the bio-oils produced contain considerable amounts of oxygen and water, they are highly corrosive and highly viscous, which limits their utility as biofuels. Pyrolysis bio-oils require upgrading to remove oxygen and corrosive components, thereby enhancing their stability for use as biofuels and their environmental sustainability. This study investigates the catalytic pyrolysis of cellulose without a catalyst and with Ga/HZSM-5 catalysts with various gallium loadings (0.3, 3 and 9 wt%) and bulk Ga₂O₃ catalysts using pyrolysis/gas chromatography–mass spectrometry (Py/GC-MS). The catalytic influence of different gallium loadings on HZSM-5 in cellulose pyrolysis reactions is discussed using a range of characterisation techniques, including ICP, XRD, N₂ porosimetry, DRIFTS, and TPRS. The main production of oxygenated compounds (furan, sugar, ketone and phenol) and hydrocarbon products, including total aromatic and monocyclic and polycyclic aromatics, as well as benzene, toluene, xylene (BTX) and naphthalene compounds, using a family of Ga-doped HZSM-5 catalysts for cellulose pyrolysis is investigated for making sustainable cellulose-derived fuel. Ga(3)/HZSM-5 formed the highest amount of aromatics, displaying that aromatic yield depends on the Brønsted-to-Lewis acid balance (2.3 ratio) and total acidity (1.03 mmol·g⁻¹), rather than on gallium loading alone. Full article