Search Results (185)

Nano- and microplastic contamination poses a growing challenge to aquatic environments, driving the need for efficient and sustainable removal technologies. In this study, carbon–silica hybrid nanoparticles (CSNPs) were synthesized from rice husk-derived black liquor via controlled lignin–silica self-assembly followed by thermal carbonization, providing a waste-recycling biorefinery route for value-added material production. Structural characterizations revealed that carbonization generates a hierarchically porous carbon–silica hybrid with enhanced surface area. The CSNPs exhibited rapid and size-dependent adsorption toward nano- and microplastics (200–1000 nm), with optimal performance observed for 500 nm particles. Microscopic observations further demonstrated a size-adaptive capture mechanism, involving pore filling and surface adsorption for nanoplastics and aggregate-assisted encapsulation for larger microplastics. This study highlights CSNPs as low-cost and effective adsorbents for broad-spectrum plastic removal while offering a sustainable pathway for the high-value utilization of black liquor and rice husk biomass in water purification applications. Full article

Micro- and nano-plastic pollution caused by the mismanagement of plastics waste is a significant problem worldwide, causing severe impacts in aquatic and terrestrial environments. The purpose of this study was to evaluate the adsorption capacity of a thermally stable and superhydrophobic bio-substrate to remove microplastic particles (MPPs) from aqueous systems. In this work, the adsorption efficiency of cattail fluff towards MPPs from pristine PP, PVC, PA6, LDPE, HDPE, and their blend was evaluated. The effect of temperature (30 °C, 40 °C, and 50 °C) and two binding environments (distilled water and industrial wastewater) on adsorption was determined. Non-linear regressions of seven adsorption isotherm models including Langmuir, Freundlich, Temkin, Dubinin–Radushkevich (D–R), Redlich–Peterson (R–P), Toth, and Sips were applied to fit the experimental data. Error function analysis confirmed that the D–R adsorption isotherm model offers the best fit of the experimental data. The results show that the bio-substrate is very effective in adsorbing MPPs from aqueous systems with adsorption capacities of q_e = 3597 mg/g and q_e = 2807 mg/g in distilled water and synthetic industrial water, respectively. The composition of the MPPs determines the effect of temperature and binding environment on the adsorption performance of the bio-substrate. Physisorption dynamics for the MPP/bio-substrate system are also provided and discussed. Overall, the hydrophobic bio-substrate is highly effective in removing MPPs from aqueous systems, with the added advantages of low cost, sustainability, and scalability for practical applications. Full article

Microplastic pollution has emerged as a major environmental concern due to its persistence, widespread distribution and potential risks to ecosystems and human health. Among the various types of microplastics, fibrous microplastics (FMPs) account for 60% to 90% of all detected microplastic particles in surface waters, primarily originating from synthetic textile production, laundering, and wastewater discharge. Their elongated morphology, high aspect ratio, and complex surface chemistry differentiate them significantly from microplastic fragments or beads, creating unique challenges for effective removal in water treatment systems. In recent years, engineered biochar has attracted increasing attention as a promising and sustainable material for microplastic removal due to tunable pore structure, surface chemistry, and adsorption capacity. However, existing reviews largely discuss microplastic removal in general terms, with limited attention to the distinctive properties of textile FMPs and their implications for biochar design and performance. This review provides a comprehensive and focused analysis of the functional characteristics of biochar that enable the effective removal of textile FMPs in water systems. First, the environmental significance and physicochemical characteristics of textile-derived FMPs are summarized. Next, the major mechanisms governing biochar–microplastic interactions, including physical interception, adsorption, and aggregation processes, are discussed. The review then examines key functional characteristics of engineered biochar, such as pore structure, surface functional groups, hydrophobicity, and composite modifications, that enhance the sequestration of FMPs. Finally, current technological challenges, research gaps, and future directions for developing scalable biochar-based solutions for textile microplastic mitigation are discussed. By linking the unique properties of textile FMPs with the functional design of biochar, this review provides a framework to guide the development of more effective and sustainable treatment strategies for reducing microplastic contamination in aquatic environments. Full article

One of the main sources of microplastic pollution in aquatic ecosystems is municipal wastewater, and preserving the ecological security of water depends on its effective removal. In this study, a potential multi-functionalized nanocomposite (NH₂-MIL-101(Fe)/CS/GO), which consists of an iron-based metal–organic framework (NH₂-MIL-101(Fe)) integrated with chitosan (CS) as a biopolymer matrix and graphene oxide (GO) as a conductive support, was exploited to enhance microplastic removal via different adsorptive hydrophilic/hydrophobic interactions. According to adsorption tests, the removal efficiencies of NH₂-MIL-101(Fe)/CS/GO for polyethylene terephthalate (PET) and polystyrene (PS) microplastics (25–30 μm) were 93.8% and 89.7%, respectively, at pH 6.2 and for 40 min of contact time. Adsorption isotherms were well fitted to both the Langmuir and the Freundlich models, and the maximum adsorption capacities of PET and PS were 321.4 and 255.1 mg·g⁻¹, respectively. The removal efficiency reached 92.5% after six cycles. The proposed MOF-based CS/GO nanocomposite provides an efficient and durable method of controlling microplastic contamination in urban wastewater. The developed multi-functionalized nanocomposite offers excellent electrostatic and hydrophobic synergy through a large surface area and π–π interactions for GO, positively charged CS, and a very high surface area with tunable porosity for the amino–MIL-101 (Fe) moiety. The proposed MOF-based nanocomposite provides an effective and persistent method of reducing microplastic contamination in constructed wetlands and water/wastewater treatment plants. Full article

Understanding the adsorption of organic pollutants onto microplastics in aqueous environments is crucial for assessing their environmental behavior and ecological risks. Herein, we used density functional theory (DFT) computations to simulate the aqueous adsorption of 54 organic compounds onto three representative microplastics, namely polyethylene (PE), polyoxymethylene (POM), and polyvinyl alcohol (PVA). Afterwards, based on theoretical molecular structural descriptors, we developed six quantitative structure activity relationship (QSAR) models based on datasets of 43 and 54 organic compounds, respectively. The results demonstrated that the oxygen-containing POM and PVA microplastics exhibited weaker adsorption in the aqueous phase compared to that in the gas phase. Furthermore, it revealed that the electron-rich atoms, van der Waals volumes and molecular polarizability exert substantial effects on the adsorption process on microplastics in water. These robust QSAR models can enable the prediction of adsorption energies for various organic pollutants on microplastics, which can offer a rapid approach for generating adsorption data. Moreover, the insights into adsorption mechanisms can provide a theoretical basis for designing modified or alternative plastics with lower environmental risks. Full article

The widespread use of plastics has inevitably led to the accumulation of persistent plastic debris in aquatic systems, where gradual fragmentation generates microplastics (MPs) that threaten ecological and biological health. Their small size, chemical stability, and resistance to degradation make effective removal particularly challenging. In this work, a composite adsorbent was fabricated through the in situ solvothermal growth of Materials of Institute Lavoisier 100 (Iron) (MIL-100(Fe)) onto coconut shell-derived activated carbon (CSAC), yielding a monolithic material denoted as CSAC@MIL-100(Fe). The integration of porous C with a metal–organic framework created a hierarchically structured adsorbent rich in accessible binding sites. The composite achieved a maximum polystyrene (PS) removal efficiency of 97.4% and maintained 91.44% efficiency after seven regeneration cycles. Stable adsorption performance was observed across a broad pH range. Structural and chemical analyses (scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS)) combined with adsorption modeling revealed heterogeneous multilayer adsorption behavior consistent with the Freundlich isotherm and pseudo-second-order kinetics. π–π interactions, electrostatic attraction, and coordination effects jointly governed PS capture. The Langmuir maximum adsorption capacity reached 746.27 mg/g. These findings demonstrate a practical and recyclable strategy for efficient MP remediation in aquatic environments. Full article

The accumulation of microplastics (MPs) in agricultural soils and atrazine in agricultural soils creates compound pollution that severely threatens soil health. The present study aimed to evaluate the effect of polyethylene (PE), polyvinyl chloride (PVC), and polybutylene succinate (PBS) on the adsorption and degradation of atrazine in yellow-brown and black soil. Batch adsorption kinetic and isotherm experiments were conducted in two distinct soils amended with MPs. A 90-day degradation experiment was performed to monitor atrazine persistence and the activities of key soil enzymes. The adsorption process was best described by the pseudo-second-order model and the Freundlich isotherm model, suggesting dominant chemisorption and multilayer adsorption on heterogeneous surfaces of the soil–MP composites. All MPs significantly enhanced the adsorption capacity for atrazine (6.80–39.93 mg kg⁻¹), with the order PBS > PE > PVC. Furthermore, the degradation of atrazine was impeded by all MPs, with PVC exhibiting the strongest inhibitory effect. The half-life of atrazine ranges from 22.97 to 81.76 days in two soils. The presence of MPs also influenced soil enzyme activities and the effects varied by MP type and soil property. These results demonstrate that MPs can modify the adsorption and persistence of atrazine in soil, thereby increasing its environmental risk. This study provides valuable insights for the long-term ecological risk assessment of co-existing MPs and pesticide pollution in terrestrial environments. Full article

Accumulation of microplastics (MPs) in aqueous environments poses a serious ecological problem nowadays. MP particles are able to adsorb pollutants of different kinds and to transport them to living organisms, leading to biotoxicity. Hence, investigation of the adsorption of pollutants of different molecular weights onto MP particles is an important task. We employed the numerical Scheutjens–Fleer self-consistent field method to study (i) the formation of MP particles consisting of homopolymer macromolecules and (ii) the adsorption of pollutant homopolymer chains onto the MP particles. Under poor solvent conditions, the polymer macromolecules were shown to form MPs with a constant density inside the particle and with an interfacial layer at its periphery. The size of the MP particles and the thickness of the interfacial layer were controlled by the solvent quality. MP particles were shown to adsorb pollutant polymer chains from the surrounding liquid due to higher compatibility of the MP particle with the pollutant polymer chains as compared to the solvent. The amount of adsorbed polymer pollutant increased with the increase of its concentration in solution. Softer MP particles were shown to adsorb larger amounts of pollutants due to a broader interfacial layer. The conformational characteristics of the adsorbed polymer chains (trains, loops, and tails) were studied in detail. Full article

Thallium (Tl) contamination of soils in lead-zinc mining areas poses potential ecological risks, and the impact of microplastics on Tl accumulation by hyperaccumulator plants remains unclear. This study examined soils collected from the Daliangzi lead-zinc mining area to investigate the characteristics of Tl contamination. These soil samples were used in plant cultivation experiments. The thallium contents in both the soil and plant samples were determined using acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS). The contamination level, plant enrichment capacity, and ecological risk were then comprehensively evaluated through the Geo-accumulation index (I_geo), Bioconcentration factor (BCF), and potential ecological risk index. The results indicated that the I_geo of Tl in the soil was 2.413, corresponding to a moderately to heavily polluted level, which necessitates focused attention. Polyethylene exhibited markedly opposing effects on Pteris vittata and Solanum nigrum: it significantly promoted Tl accumulation in the former, while distinctly inhibiting it in the latter. Microplastics could modify the pH value of soil, as well as the contents of nitrogen (N) and phosphorus (P). Risk assessment indices indicated that Tl pollution in this region reaches a very high contamination level with moderate potential ecological risk. Polyethylene and polypropylene demonstrated a species-specific promoting effect on Tl adsorption by the two hyperaccumulator plants, with polyethylene significantly enhancing the Tl accumulation capacity of P. vittata and polypropylene distinctly promoting Tl adsorption in S. nigrum. Full article

Reliable detection of microplastics by surface-enhanced Raman scattering (SERS) is often hindered by poor particle–substrate contact and limited access to plasmonic hotspots on conventional planar substrates optimized for molecular adsorption. Here, we report a rapid microwave-assisted carbothermal shock strategy to fabricate silver nanoparticle-decorated electrospun carbon fibers (AgNPs@ECF) as a three-dimensional plasmonic platform tailored for solid microplastic sensing. Localized microwave-induced heating in a mixed ethanol–hexane system enables Ag nanoparticle nucleation and anchoring on conductive carbon fibers within 45 s, yielding a mechanically compliant, junction-rich architecture without chemical reductants or vacuum processing. The AgNPs@ECF composite was evaluated using morphologically weathered polystyrene (PS) and polyethylene terephthalate (PET) microplastics, along with size-controlled PS bead standards ranging from ~50 nm to 45 μm. Across these models, SERS response is governed primarily by particle–substrate contact geometry and near-field accessibility rather than polymer type. The strongest enhancement occurs in the sub-micrometer regime, where particles can engage multiple AgNP-decorated fiber junctions, while ultrasmall and large, smooth particles show reduced enhancement due to limited contact or rapid field decay. Spatially resolved Raman mapping and finite-difference time-domain simulations support a contact-dominated enhancement mechanism, revealing localized field confinement at particle–fiber interfaces. These results establish the design principles for three-dimensional SERS substrates targeting heterogeneous solid particulates, demonstrating that contact-accessible plasmonic architectures are critical for reliable microplastic detection under realistic solid-particle measurement conditions. Full article

Oxybenzone (BP-3) and polystyrene microplastics (PS MPs) are pervasive aquatic contaminants whose combined biological effects remain insufficiently characterized. This study investigated co-exposure to BP-3 and PS MPs in zebrafish embryos (Danio rerio), focusing on developmental endpoints, tissue bioaccumulation, and time-dependent sorption behavior. Embryos were exposed to 0.10–1.50 mg/L BP-3 for 96 h in the presence of PS MPs. Mortality, developmental abnormalities, and tissue BP-3 concentrations were measured, and chemical analysis was performed by HPLC-DAD. Although mortality was not significantly affected, embryos exhibited developmental abnormalities, particularly in swim bladder formation. Tissue BP-3 accumulation increased with exposure concentration. The influence of PS MPs on BP-3 uptake was concentration-dependent: at lower BP-3 exposures, PS MPs reduced tissue accumulation, whereas at higher exposures this reduction became negligible or was no longer observed. This suggests a dual role for PS MPs: mitigating direct aqueous exposure by sequestering BP-3 yet simultaneously acting as potential vectors for its environmental persistence and trophic transfer through alternative pathways. Independent time-resolved experiments showed rapid BP-3 removal from the aqueous phase in the presence of PS MPs, with early stabilization consistent with rapid partitioning behavior. These findings highlight the complex interactions between emerging contaminants and MPs, underscoring the need for further research into their ecological implications. Full article

The rapid growth of synthetic textile production has intensified the release of micro- and nanoplastics (MPs/NPs) into aquatic environments, primarily through industrial effluents and domestic laundering. Textile-derived microplastics, especially polyester fibers and polymeric coating fragments, constitute a significant fraction of plastic contamination in wastewater systems. Although wastewater treatment plants (WWTPs) can remove a large proportion of MPs, substantial quantities accumulate in sewage sludge, raising concerns about long-term environmental persistence and secondary release pathways. This review critically examines the sources, classification, and release mechanisms of textile-based micro- and nanoplastics, including fibrous debris and coating-derived fragments. Then it focuses on current identification and removal technologies, such as sedimentation, coagulation/flocculation, electrocoagulation, flotation, membrane filtration, adsorption, and biodegradation, and on the emerging strategy of converting recovered microplastics into value-added porous carbon materials via hydrothermal treatment and pyrolysis. Carbonized microplastics exhibit high surface area and adsorption capacity for dyes, heavy metals, and organic pollutants, offering a circular approach that simultaneously mitigates plastic pollution and enhances wastewater treatment efficiency. By integrating source control, optimized removal technologies, and carbonization-based valorization, this review proposes a dual-benefit framework that transforms textile-derived microplastic waste from an environmental liability into a functional resource for sustainable water purification. Full article

Microplastic (MP) pollution represents a significant environmental threat, impacting aquatic ecosystems and human health. This review examines critical elements of MP risk assessment, including exposure pathways, properties (polymer type, size, and shape), bioaccumulation, and ecological and health effects. It underscores the challenges of quantifying MP exposure and identifying pollutants, as well as gaps in understanding pollutant adsorption/desorption and biofilm impacts. MPs serve as carriers for organic pollutants, heavy metals, and chemical additives, potentially magnifying toxic effects. Emerging contaminants, such as pharmaceuticals, exacerbate these risks. Laboratory research is crucial to trace MPs through food chains from primary producers to humans and assess bioaccumulation and health impacts. Current assessments, however, are insufficient to provide comprehensive ecological risk evaluations. The review highlights the need for improved methodologies to assess MPs’ fate, trophic transfer, and long-term ecological effects. MPs often release harmful additives like plasticizers and flame retardants, necessitating studies to differentiate the impacts of polymers and additives. It emphasizes integrating MP toxicity data into risk models while fostering collaboration among scientists, policymakers, and communities. The paper advocates for a comprehensive framework combining advanced analytical methods and environmental monitoring to refine risk assessment models. These efforts aim to strengthen public awareness, support informed environmental policies, and promote sustainable practices to mitigate MP pollution impacts. Addressing these research gaps will significantly enhance the scientific understanding of MP risks and guide effective management strategies for environmental and human health protection. 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

Microplastics (MPs) and emerging contaminants (ECs) are increasingly prevalent in environments due to their persistence, toxicity, and resilience against standard wastewater treatment methods. This review presents a comprehensive analysis of contemporary and advanced membrane-based techniques, highlighting their removal efficacy, recovery potential, and fundamental mechanisms such as size exclusion, adsorption, electrostatic interactions, and biodegradation. This review emphasizes the physicochemical properties of MPs, including particle size, shape, polymer type, and hydrophobicity, and their significant impact on membrane performance and fouling behavior. Key findings reveal that membrane fouling is a primary constraint affecting operational efficiency. This study identifies the types of fouling standard, total, intermediate, and cake formation that contribute to flux deterioration and necessitate increased energy expenditures during prolonged operation. Additionally, this research highlights the detrimental effects of mechanical abrasion and scaling on membrane integrity and lifespan. Future prospects for membrane technology are explored, positioning it as a leading solution for sustainable wastewater treatment. Essential directives include the development of intelligent membranes responsive to environmental stimuli, AI-driven monitoring systems, and modular and decentralized treatment units. Moreover, the implementation of circular economy principles is discussed, emphasizing concurrent treatment and resource recovery, such as nutrients, biogas, and clean water. The regulatory and legislative implications of membrane-based treatment are also addressed, underscoring the importance of standardization, performance evaluation, and sustainability. Ultimately, this analysis positions membrane technologies as pivotal instruments in the advancement of intelligent, energy-efficient, and regenerative wastewater management systems. Full article