Search Results (524)

Municipal sludge generation has increased rapidly with urbanization, creating significant challenges for sustainable waste management. This review proposes a system-oriented framework for sludge resource utilization by linking sludge characteristics, conversion technologies, environmental risks, and product applications. Major treatment pathways, including anaerobic digestion, pyrolysis, ozonation, and hydrothermal carbonization, are critically compared, with emphasis on their inherent trade-offs between resource recovery, energy consumption, and contaminant control. Particular attention is given to emerging contaminants, such as microplastics, per- and polyfluoroalkyl substances (PFAS), and antibiotic resistance genes, where the distinction between pollutant removal and actual risk reduction remains insufficiently addressed. The review highlights that no single technology can achieve optimal performance under all conditions, and integrated treatment trains are generally required for sustainable sludge management. Among these pathways, pyrolysis shows considerable potential for applications requiring enhanced contaminant control and value-added biochar production due to its ability to promote organic contaminant degradation, heavy metal immobilization, and carbon storage. However, the feasibility of pyrolysis and other technologies depends strongly on site-specific factors, including sludge properties, energy availability, economic conditions, and regulatory requirements. Future research should focus on integrated process optimization, comprehensive pollutant fate assessment, and standardized evaluation frameworks to advance sludge management toward a circular economy. Full article

Microplastics (MPs) pollution caused by agricultural film residues, organic fertilizer application, sewage irrigation, and atmospheric deposition has gradually become an unignorable interference factor to the sustainable development of the rhizosphere soil and crop in farmland. However, their specific impacts on the rhizosphere and crops remain unclear. Therefore, this review focuses on the current knowledge on the response mechanisms of rhizosphere soil and crops to MP contamination. The density of MPs is generally lower than that of soil mineral particles. Their substantial accumulation in soil can significantly reduce both the bulk density (by increasing total porosity) and the particle density (by diluting the heavy solid phase with light plastic components). The introduction of MPs disrupts the normal metabolism of soil bacterial communities; a disruption directly reflected in functional genes associated with carbon cycling. MPs can interfere with the activity of key metabolic enzymes involved in fungal nutrient cycling, thereby disrupting normal energy allocation and material metabolism. Viruses can regulate the turnover and metabolism of microbial communities through lytic and lysogenic cycles, consequently influencing the carbon fate of MPs. The toxicity and underlying mechanisms of MPs on soil fauna primarily manifest in aspects such as feeding behavior, growth and development, oxidative stress, intestinal toxicity, and reproductive toxicity. The direct effects of MPs on plants include physical barriers and mechanical damage, induction of oxidative stress, interference with nutrient uptake, disruption of photosynthesis and carbon metabolism, and disruption of plant hormone networks. This review identifies critical knowledge gaps, particularly regarding crop quality, field-based soil faunal studies, virus-microbe interactions, and degradation products, and proposes future research directions to better understand the risks MPs pose to agricultural sustainability and food safety. Full article

Microplastics have emerged as a persistent and prevalent threat to human health and the marine environment due to their widespread use and poor management, including low recycling rates, inadequate waste management, improper disposal, and inadequate control of plastic leakage into the environment. Plastic pollution is transported to the marine ecosystem through both ocean-based and land-based pathways and can be fragmented into microplastics (<5 mm) and nanoplastics (<1 µm). The study explains the sources, distribution, mechanisms of degradation, and transport pathways to the marine environment. Land-based activities are recognized as the dominant source, causing approximately 70–80% of marine plastic pollution. Domestic greywater is highlighted as a significant and common source of microplastics due to the release of microbeads and synthetic fibers from different sources, such as laundry, washbasins, and personal care products (PCPs). Similarly, greywater release from maritime vessels and cruise ships significantly contributes to marine microplastic pollution. The study discusses the biotic and abiotic degradation mechanisms. The health and environmental effects of microplastics are measured across different trophic levels. Ingestion and bioaccumulation of microplastics can cause physiological and reproductive disturbances. Human exposure through seafood consumption and inhalation may result in skin infections, cardiovascular complications, gastrointestinal disorders, and respiratory problems. The mitigation and control measures include improvements in wastewater treatment, public awareness, policy regulations, and biodegradable alternatives to support sustainable protection of the marine environment. Full article

Background/Objectives: Microplastics (MPs) and nanoplastics (NPs) have emerged as ubiquitous environmental contaminants resulting from the extensive production, use, and degradation of plastic materials. Human exposure occurs primarily through contaminated food and drinking water, with inhalation representing an additional important route. Growing concern has focused on the ability of these particles, particularly NPs, to cross biological barriers, enter the systemic circulation, and reach human tissues. The aim of this review was to summarize current evidence on dietary exposure to MPs and NPs, their gastrointestinal bioavailability and toxicokinetics, and their potential systemic health effects, with particular emphasis on organ-specific responses, underlying biological mechanisms, and the strength and limitations of the available evidence. Methods: A comprehensive narrative review of the scientific literature published between 2000 and 2026 was conducted using PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar. Original research articles and review papers addressing dietary exposure, occurrence in food and drinking water, migration from food-contact materials, gastrointestinal absorption, translocation, biodistribution, bioaccumulation, elimination, molecular mechanisms, and potential organ-specific or systemic health effects were included. Publications without full-text availability, conference proceedings, editorials, commentaries, duplicate publications, and studies without relevance to human exposure or health were excluded. Results: Food, drinking water, beverages, and food-contact materials represent important sources of human exposure to MPs and NPs. Following ingestion, most larger particles are eliminated through the gastrointestinal tract, whereas smaller MPs and particularly NPs may cross biological barriers and potentially reach the systemic circulation and distant tissues. Experimental studies consistently identify interconnected biological responses involving oxidative stress, inflammation, mitochondrial dysfunction, barrier impairment, immune dysregulation, genotoxicity, apoptosis, and endocrine disruption. These mechanisms have been associated with alterations in the gastrointestinal, respiratory, cardiovascular, nervous, urinary, reproductive, endocrine, and skeletal systems and with biological processes relevant to carcinogenesis. However, most mechanistic evidence derives from in vitro and animal models, whereas human evidence remains limited and predominantly observational. Consequently, the extent to which these experimental findings translate into clinically significant effects in humans remains uncertain. Conclusions: Current evidence supports the biological plausibility of systemic effects associated with MNP exposure but is insufficient to establish causal relationships between chronic dietary exposure and specific human diseases. The detection of MNPs in human tissues and reported associations with pathological conditions should therefore be interpreted cautiously. Standardized analytical methods, improved characterization of realistic human exposure, and well-designed longitudinal epidemiological studies integrating quantitative exposure assessment with validated clinical outcomes are required to clarify dose–response relationships, long-term health effects, and the clinical significance of MNP exposure. Full article

Adaptive feedback can destabilize a loop that would be stable under any fixed gain, so the speed at which the gain adapts is itself a design parameter. We study this effect in a minimal three-dimensional model motivated by the photocatalytic degradation of microplastics: a pollutant concentration is driven toward a setpoint by an ultraviolet (UV) actuator whose gain adapts online. The model has a single bilinear nonlinearity, so the local analysis can be carried out in closed form. Under an explicit feasibility condition, the system has a unique positive equilibrium. The Routh–Hurwitz criterion shows that this equilibrium is locally asymptotically stable below an explicit critical adaptation speed ${\kappa }_c$ and unstable above it. At $\kappa ={\kappa }_c$, a purely imaginary eigenvalue pair crosses the imaginary axis transversally, and a Hopf bifurcation occurs, with an explicit onset frequency. The first Lyapunov coefficient is computed in closed form; it separates a supercritical onset, for well-damped actuators, from a subcritical onset with hysteresis, for weakly damped actuators. Numerical experiments confirm the predicted limit cycle and the classification. All the stability results established here are local. Full article

Polystyrene (PS) thermal degradation involves localized molecular bond-cleavage events that are not directly equivalent to the apparent kinetic parameters obtained from bulk thermal analysis. In this study, a finite hydrogen-terminated PS oligomeric model was examined using density functional theory at the M06-2X/LANL2DZ level, whereas the non-isothermal degradation behavior of a PS sample was independently evaluated by thermogravimetric analysis under nitrogen. The computational analysis considered frontier molecular orbital distributions and site-specific thermodynamic descriptors associated with homolytic C–C cleavage and radical-mediated β-scission reactions. The calculated HOMO–LUMO gap of 742.62 kJ mol⁻¹ indicated a comparatively large orbital-energy separation within the selected oligomeric model, while the localization of the frontier orbitals over aromatic and benzylic regions revealed a spatially heterogeneous electronic distribution. Homolytic C–C cleavage exhibited bond dissociation energies ranging from 414.09 to 481.24 kJ mol⁻¹, demonstrating that the thermodynamic requirement for radical generation depends on the local molecular environment of the evaluated structure. The Gibbs free-energy changes calculated for the selected radical β-scission reactions ranged from 55.44 to 189.41 kJ mol⁻¹. These quantities represent model-dependent reaction thermodynamics and should not be interpreted as activation barriers because transition states were not calculated. Thermogravimetric analysis showed systematic increases in Tonset and Tmax with increasing heating rate, consistent with kinetic delay and thermal-lag effects under non-isothermal conditions. The Kissinger method yielded a global apparent activation energy of 186.61 kJ mol⁻¹, whereas the residual-mass-corrected Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods produced average apparent activation energies of 180.81 and 178.49 kJ mol⁻¹, respectively, over α = 0.05–0.95. Across the same conversion interval, the FWO apparent activation energy increased from 143.10 to 221.71 kJ mol⁻¹, while the KAS values increased from 140.10 to 220.23 kJ mol⁻¹, indicating an evolving macroscopic degradation response with greater uncertainty toward high conversion. The computational and experimental datasets were therefore interpreted as complementary but non-equivalent scale-dependent descriptions: DFT compares the relative thermodynamics of selected molecular reactions within a finite isolated oligomer, whereas TGA characterizes the global apparent kinetic behavior of the condensed polymer sample. No direct numerical correspondence was established between the molecular reaction energies and the TGA-derived apparent activation energies, and no individual cleavage reaction was assigned to a specific conversion interval. Extrapolation of these results to high-molecular-weight, polydisperse, additive-containing, cross-linked, or environmentally aged PS microplastics should therefore be made with caution. Full article

Polyethylene (PE) microplastics are environmentally persistent contaminants whose progressive fragmentation suggests that degradation may not be governed by uniform backbone stability. In this work, density functional theory and non-isothermal thermogravimetric analysis were combined to evaluate PE degradation from complementary molecular and kinetic perspectives. A C₉₀H₁₈₂ polyethylene oligomer was optimized at the M06-2X/def2-TZVP level, and position-resolved C–H and C–C bond dissociation energies were calculated along the chain. The C–H bonds showed comparatively high and homogeneous stability, whereas the C–C backbone displayed lower dissociation energies and a localized energetic depression in the central region. The minimum C–C BDE was found at C44, with a value of 85.73 kcal·mol⁻¹, identifying a model-specific low-BDE region within the finite all-trans-derived oligomer that may favor backbone scission under the evaluated computational conditions. Thermogravimetric analysis under nitrogen at 5, 10, and 20 °C min⁻¹ showed a dominant degradation event, with DTG maxima shifting from 462.6 to 494.6 °C as the heating rate increased. Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose analyses revealed a progressive increase in apparent activation energy from approximately 170–175 kJ·mol⁻¹ at low conversion to 280–285 kJ·mol⁻¹ at high conversion. Although BDE and apparent activation energy are not directly equivalent, their combined interpretation supports a heterogeneous degradation model in which PE fragmentation preferentially initiates at localized low-BDE C–C environments before progressing toward regular backbone scission and secondary degradation reactions. Full article

Microplastics (MPs), defined as plastic particles smaller than 5 mm in diameter, are an emerging class of environmental contaminants of global concern. As the “Water Tower of Asia” and a critical global ecological barrier, the environmental condition of the Qinghai–Tibet Plateau has a direct influence on the ecological security of major river systems and the well-being of populations downstream. MPs have now been detected across multiple environmental compartments on the plateau, including soils, water bodies, and glaciers. Given the fragility and ecological uniqueness of the region, systematic investigation of plastic pollution here is essential for safeguarding its ecological security. Based on current research, existing data on MP pollution across the Qinghai–Tibet Plateau are reviewed and synthesized. Evidence suggests that the abundance of MP varies significantly across different environmental media in various regions and is influenced by multiple factors. Two major potential sources are identified: local anthropogenic activities and transboundary inputs via atmospheric transport and other pathways. The unique environmental conditions of the region, such as intense ultraviolet radiation, large day–night temperature variation, and frequent high-wind events, provide a distinctive setting for the migration, dispersion, transformation, and degradation of MPs across environmental matrices. Understanding the distribution, sources, and migration patterns of microplastics on the Qinghai–Tibet Plateau will help facilitate sustainable environmental management, ecosystem conservation, and pollution control in these fragile high-altitude regions. Full article

Microplastics are plastic particles smaller than 5 mm that have become a growing environmental concern due to their persistence and widespread distribution. They originate from diverse sources, including laundry detergents, vehicle tires, cosmetic microbeads, and the degradation of larger plastics through ultraviolet radiation and saline exposure. This systematic review was conducted following the PRISMA guidelines to summarize current knowledge on the environmental and human health effects of microplastics. A comprehensive literature search was performed in ScienceDirect, PubMed, Web of Science, and Google Scholar databases, yielding 2694 initial records. After applying exclusion criteria and removing duplicates, 111 studies were selected for full reading, and 54 articles were ultimately included in the analysis. The results reveal that microplastics can absorb and release pollutants, leading to the contamination of water and soil and enabling them to enter the food chain, thereby posing potential risks to both ecosystems and human health. However, significant discrepancies were found among the databases regarding the amount and quality of available data, highlighting the need for standardized research approaches. In conclusion, understanding the sources, distribution, and impacts of microplastics is crucial to developing strategies to mitigate their release, and further research is essential to assess their long-term effects and to guide environmental policy. Full article

In recent years, plastic litter in marine ecosystems has emerged as a global concern. Consequently, efforts to control, mitigate, and remove micro- and macroplastics from marine systems have intensified. In order to thoroughly analyze this topic, the present work provides a comprehensive overview of various strategies aimed at reducing plastic waste pollution spread in marine areas. Based on this, worldwide regulations limiting single-use plastic (SUP) products and microplastics in health care products were discussed. Further attention was also paid to bioplastic production as a potential alternative to non-degradable ones, with particular attention to their different degradability rates in various environmental compartments. Finally, strategies for the reduction in plastic pollution were specifically analyzed through a review of plastic litter collection/removal systems from beaches and the marine environment as well as different waterways. According to the above-mentioned aspects, this work highlights the significance of marine plastic litter pollution and provides support for the identification and selection of effective strategies for the mitigation of the impact of such litter on the environment. Full article

Plastic contamination (plastamination) is one of the main challenges of the 21st century. Microplastics (MPs, 5 mm–1 µm) and nanoplastics (NPs, <1 µm) are mainly produced from the environmental degradation of plastic waste and enter the food chain, bypass biological barriers, and bioaccumulate in tissues where they exert toxic/inflammatory effects. In the male reproductive system, MP/NPs can cross the blood–testis barrier, impair spermatogenesis, and affect semen quality parameters. While biodegradable polymers like polylactic acid (PLA) may represent an ecofriendly alternative to carbon fossil polymers, their real effects in reproduction have been poorly investigated. In the present manuscript, the effects of increasing doses of rhodamine B-loaded PLA-NPs (170 ± 20 nm mean size) on the physiology of frozen–thawed bovine sperm were investigated using a computer-assisted sperm analyzer (CASA) and flow cytometry. Sperm kinetics revealed a significant effect of PLA-NPs on progressive motility at 60 min, with higher values at 200 and 300 µg/mL doses (p < 0.05 vs. control). Flow cytometry showed that PLA-NP exposure did not alter acrosomal integrity (PNA488+); however, the proportion of spermatozoa showing high mitochondrial potential (MitoDR+) was significantly reduced compared to controls at a 300 µg/mL PLA-NP dose after 120 min of incubation. The proportion of spermatozoa metabolically active (MitoDR+) with contextual membrane destabilization (M540+) was significantly lower in samples with 200 and 300 µg/mL PLA, independently of the incubation time. Finally, immunofluorescence analysis revealed the internalization of PLA-NPs within spermatozoa at the longest exposure time. In conclusion, PLA-NPs are internalized in spermatozoa, with specific localization in mitochondria, and slightly affect progressive motility mainly by mitochondrial interference and plasma membrane destabilization. Despite limited effects on post-thaw bull sperm motility even at high doses, plastamination warrants consideration, and further studies on the biological effects of biodegradable plastics are recommended to preserve sperm physiology. Full article

The increasing use of plastics in agriculture has enhanced crop productivity, water-use efficiency, and food supply stability. Nevertheless, the ongoing degradation of agricultural plastics and waste-derived materials has resulted in the widespread occurrence of microplastics (<5 mm) and nanoplastics (<1 μm) in agricultural soils, raising concerns about ecosystem functioning, food safety and human health. This review was conducted using literature obtained primarily from Web of Science, Scopus and PubMed. Publications published between 2019 and 2026 were primarily included. In addition, selected landmark studies published before 2019 were incorporated when they provided foundational concepts, methodological frameworks, or highly cited evidence that remains essential for understanding the sources, fate, and impacts of micro- and nanoplastics in agricultural systems. The review synthesizes recent scientific evidence regarding the sources, environmental fate, biological interactions, and food-chain transfer of micro- and nanoplastics within agricultural and food production systems, tracing their movement from farm to fork. Major contamination pathways include agricultural plastic materials, organic amendments, polymer-coated agrochemicals and atmospheric deposition. Mechanisms governing transport, aging, plant uptake and trophic transfer are also discussed. Current evidence suggests that agricultural soils are among the largest terrestrial reservoirs of micro- and nanoplastics; however, substantial uncertainties remain regarding environmental concentrations, plant uptake under field conditions, and human health risks due to methodological limitations and the lack of standardized analytical protocols. Future research should focus on standardized monitoring methods, enhanced risk assessment frameworks, the development of biodegradable alternatives, and integrated mitigation strategies to reduce plastic contamination. Full article

Food contaminants, including plasticizers, pesticide residues, heavy metals, and biotoxins, pose persistent risks to food quality and human health. Their diverse sources, complex migration pathways, and potential long-term toxicity make removal difficult. Conventional removal technologies, such as physical treatment, chemical degradation, adsorption, membrane separation, and biological methods, can reduce contaminant levels to varying degrees. However, they often show limited selectivity, matrix interference, harsh operating requirements, or losses of nutritional and functional components. Molecularly imprinted polymers (MIPs) are synthetic recognition materials with binding sites tailored to a target contaminant. Their template-induced cavities provide complementarity in size, shape, and functional-group arrangement, enabling selective adsorption in complex matrices. Recent studies apply MIPs to the enrichment, detection, and removal of plasticizers, pesticide residues, heavy metals, and biotoxins. Unlike recent surveys centered on MIP-assisted analysis and sensing, this review uses contaminant removal as the organizing problem and compares MIP-based strategies with conventional decontamination across four hazard classes. MIPs offer tunable selectivity, chemical stability, and reusability, but practical food applications still face template leakage, slow mass transfer, incomplete safety evaluation, matrix dependence, and scale-up limitations. Future work should prioritize green synthesis, surface imprinting, magnetic recovery, and systematic validation in real food matrices. To prevent analytical extraction from being conflated with remediation, the evidence is classified from proof-of-binding and analytical cleanup to edible-matrix treatment and process validation, and representative studies are compared using capacity, removal or recovery, equilibration time, selectivity, reuse, and matrix validation. Recent evidence also reveals substantial gaps for PFAS, microplastics, and nanoplastics: selective recognition is advancing, but food-safe removal remains largely unvalidated. Full article

The accumulation and persistence of plastic waste have made microbial plastic biodegradation an important topic in pollution control, environmental remediation, and sustainable materials management. This study combines a mini-review with bibliometric analysis to link mechanistic understanding with global research trends in microbial plastic biodegradation from 2000 to 2025. The mini-review summarizes polymer weathering and fragmentation, microbial colonization and biofilm formation, extracellular depolymerization or oxidative chain cleavage, uptake and intracellular catabolism of plastic-derived intermediates, physiological regulation, ecological interactions, and potential applications in bioremediation and upcycling. Bibliographic records were retrieved from the Web of Science Core Collection and analyzed using bibliometrix, VOSviewer, CiteSpace, and SCImago Graphica. A total of 2959 publications were identified. Publication output increased markedly, especially after 2018, reaching 617 publications in 2025; cumulative citations reached 31,373. China, India, and the United States were the leading contributors. Journal and keyword analyses showed strong links among environmental science, polymer science, microbiology, biotechnology, and engineering. Highly cited publications mainly focused on plastic biodegradability, biodegradable polymers, engineered PET depolymerization, polyethylene degradation, and microbial or enzymatic degradation mechanisms. Keyword evolution revealed a shift from material-oriented topics, including polymer blends, poly(vinyl alcohol), polyesters, morphology, mechanical properties, composites, and polyhydroxyalkanoates, toward degrading enzymes, cutinase-like enzymes, plastic-degrading strains, microbial colonization, fungi, and marine environmental degradation. Overall, microbial plastic biodegradation has evolved from material-centered biodegradability evaluation toward a mechanism-oriented and environment-oriented interdisciplinary field. Full article

CRISPR (clustered regularly interspaced short palindromic repeats)-based genome engineering is reshaping how environmental contamination can be interrogated and remediated, offering a level of programmability and specificity that conventional physicochemical workflows seldom match. Microplastics polymer fragments below 5 mm that now pervade virtually every ecosystem are especially difficult to monitor and remove because of their chemical heterogeneity, sub-millimeter size, and capacity to adsorb co-pollutants. This review examines how the molecular logic of CRISPR-Cas systems is being repurposed for two complementary goals: sensitive analytical detection and microbially driven degradation of plastic particles. We first outline the biochemistry of Cas-mediated cis- and trans-cleavage that underpins isothermal, amplification-free biosensing, and then survey direct strategies, in which polymer-binding DNA (deoxyribonucleic acid) aptamers are coupled to Cas12a (CRISPR-associated protein 12a), alongside indirect strategies that read out the molecular stress signatures provoked by microplastic exposure in sentinel organisms and plastisphere communities. On the remediation side, we discuss how targeted editing, CRISPR interference, and rationally assembled microbial consortia enhance enzymatic depolymerization and redirect carbon flux toward valuable bioproducts. By integrating detection and remediation within a single conceptual framework, we identify the principal bottlenecks, aptamer selectivity in complex matrices, reagent stability under field conditions, and host metabolic burden, and outline research priorities for translating these tools from proof of concept toward deployable environmental technologies. Full article