Search Results (2,929)

Pesticide contamination in urban runoff, stormwater, and peri-urban drainage networks is an increasing concern because of the persistence, mobility, and ecological toxicity of many pesticide residues and their transformation products. Nature-based solutions (NBSs), including constructed wetlands, bioretention systems, biofilters, and permeable reactive bio-barriers, provide low-energy and ecologically compatible platforms for urban water treatment; however, their performance is often constrained by limited sorption capacity, substrate saturation, variable hydraulic loading, and incomplete degradation of persistent pesticides. Biochar offers a multifunctional amendment for strengthening these systems because its tunable porosity, surface functionality, mineral composition, redox activity, and microbial habitat-forming capacity can support pesticide adsorption, catalytic transformation, and biodegradation. This review critically evaluates biochar-integrated NBSs for pesticide-contaminated urban water systems by linking biochar production and modification strategies with pesticide removal mechanisms, biochar–microbe interactions, engineered treatment configurations, and field-scale applicability. A comparative synthesis is provided across material-level mechanisms, system-level performance, machine learning-assisted prediction, techno-economic feasibility, life-cycle impacts, and environmental risk considerations. By integrating material properties, removal mechanisms, NBS configurations, predictive modeling, sustainability assessment, and risk considerations, this review provides a broader comparative basis than previous studies focused mainly on individual aspects of biochar-based pesticide remediation. Future priorities include standardized biochar production, long-term field validation, spent-biochar management, ecotoxicological assessment, and data-driven optimization of biochar-assisted NBSs. Full article

This work reports the development of innovative enzyme–titanium nanobiohybrids synthesized via a protein-assisted approach to obtain efficient and sustainable photocatalysts for environmental remediation. By addressing the limitations of conventional TiO₂ nanoparticle synthesis, this strategy enables controlled material properties under milder, potentially scalable conditions for enhanced ROS-driven degradation of persistent dye pollutants. This work employs a bio-assisted synthesis approach using β-glucosidase as a protein scaffold, TiCl₄ as the titanium precursor, and H₂O₂ in bicarbonate buffer at room temperature, eliminating the need for harsh conditions and high temperatures. The biological moiety guides the nanoparticle formation, controlling size and morphology while preventing aggregation, all performed under mild conditions. X-ray diffraction determined that the Ti hybrid was composed of TiO₂ brookite species. TEM analyses demonstrated the formation of well-dispersed nanostructures of around 700 nm. The resulting nanobiohybrids showed excellent photocatalytic activity, achieving >99% Rhodamine B degradation under UV light in only 1 h compared to visible light. The catalyst was capable of degrading Rhodamine B at a concentration approximately 36 times above the recommended threshold for water. Furthermore, a preactivation of the catalyst by direct exposition of it to UV-395 nm light greatly enhanced the efficiency in the photocatalytic process, being inactive in visible light. The Ti–enzyme hybrid showed excellent recyclability over five consecutive cycles and retained good activity after storage, demonstrating its stability. This study introduces a sustainable and efficient route for synthesizing Ti-based nanobiohybrids, providing a promising strategy for advanced photocatalytic applications in water treatment and environmental remediation. Full article

Cucurbiturils (CB[n]) are rigid glycoluril-based macrocycles possessing well-defined hydrophobic cavities capable of forming stable host–guest complexes in water. Owing to these properties, CB[n]-containing supramolecular polymer gels have attracted increasing attention as functional composite materials in modern materials science. This review summarizes recent progress in the development of cucurbituril-based supramolecular gels, with particular attention to synthetic approaches, network design, and emerging applications. Both conventional acid-catalyzed methods and more sustainable synthetic strategies for cucurbituril preparation and functionalization are discussed. We further consider the role of CB[n] macrocycles as reversible crosslinking units in polymer networks and analyze how host–guest interactions influence the mechanical properties, self-healing behavior, and stimuli responsiveness of the resulting materials. Recent applications in biomedical engineering, soft electronics, and environmental remediation are also highlighted, demonstrating how molecular-level supramolecular interactions can determine the macroscopic performance of these composite systems. The review concludes with perspectives on scalable synthesis, processing integration, and future directions in supramolecular composite materials. Full article

Dye removal from aqueous solutions remains a major global environmental challenge. Among the various remediation techniques, adsorption using natural materials has gained significant attention. In this study, the adsorption of methylene blue (MB) by a natural volcanic rock (VR) adsorbent—collected from the Cerro Blanco volcano in Divisaderos, Sonora, Mexico—was investigated, and the process efficiency was evaluated at different temperatures. The comprehensive characterization revealed a rough and irregular porous surface via SEM, while the EDS elemental data and the CIPW normative calculations identified the material as a silica-saturated tholeiitic basalt, primarily composed of bytownite (${An}_{71})$ and pyroxenes. This petrological classification was cross-validated by XRD and FTIR spectra, which exhibited vibrational modes characteristic of mafic silicate. The surface analysis via the BET method indicated a specific surface area of 12 m²·g⁻¹, while a BJH analysis indicated a mesoporous structure (average pore diameter of 3.75 nm), and a Type IV isotherm with H3-type hysteresis, suggesting narrow, slit-shaped pores. Batch adsorption experiments demonstrated an exceptional removal efficiency of 99.99% for 50 mg·L⁻¹ MB within only 30 min. The equilibrium data and the adsorption kinetics followed the Langmuir isotherm and a pseudo-second-order model, respectively. Cytotoxicity assays confirmed the VR is biosafe. The combination of high removal efficiency, low cost, and environmental safety positions this material as high-potential adsorbent for sustainable water remediation processes. Full article

CdS and Cd-deficient CdS (D-CdS) were prepared using a simple hydrothermal method. Pristine CdS exhibited slow electron transfer and limited active sites in periodate (PI) activation, while Cd vacancy defect engineering proposed in this work effectively overcame these drawbacks. The optimal Cd-deficient D-CdS8 could effectively activate PI and exhibit excellent degradation performance toward tetracycline (TC). Within 90 min, the D-CdS8/PI system could achieve 92.3% removal of 10 mg L⁻¹ TC. This study systematically explores the influences of different factors and coexisting substances on TC degradation. Radical quenching experiments revealed that IO₃· and ·OH were the dominant reactive species for TC degradation in D-CdS8/PI system. Electrochemical characterization indicated that the introduction of Cd vacancies made D-CdS8 possess higher electron transfer efficiency. The D-CdS8/PI system achieved enhanced PI activation and improved TC degradation, with reaction rates 2.15 times superior to the CdS/PI system. Furthermore, degradation pathways and toxicological analysis of intermediates for TC degradation were also conducted. This study provided a simple and feasible strategy for developing efficient defective catalysts for the remediation of antibiotic-contaminated water. Full article

This study addresses the critical challenge associated with the removal of reactive yellow dyes from aqueous media and industrial wastewater streams. Owing to their pronounced chemical stability and resistance to conventional degradation techniques, such dyes constitute a substantial environmental concern. In this context, the present work investigates the efficacy of unmodified magnetite nanoparticles (plate-like rounded structures 6–23 nm in size), synthesised under rigorously controlled conditions and well characterised, as high-performance adsorbents for the sequestration of persistent dye species exhibiting limited susceptibility to rapid degradation. The effects of key operational parameters on dye removal efficiency were systematically evaluated to establish optimal treatment conditions. Complete removal of reactive yellow dye (100%) was achieved within 30 min at low initial dye concentrations (20 mg/L) under mildly acidic conditions and continuous agitation. Adsorption equilibrium studies, interpreted using the Langmuir isotherm model, revealed a maximum adsorption capacity of 33 mg/g under optimised conditions. Thermodynamic analysis indicated that the adsorption process is spontaneous (−ΔG° ≈ 46–54 kJ/mol) and endothermic (ΔH° = 21.12 kJ/mol), accompanied by an increase in system disorder (ΔS° = 0.2 kJ/mol × K). Importantly, experiments conducted using real wastewater matrices demonstrated performance comparable to that obtained in deionised water, thereby underscoring the practical applicability of the proposed system. Furthermore, the nanoparticles retained more than 90% removal efficiency after five consecutive adsorption–desorption cycles, employing a basic eluent for dye desorption and surface regeneration. The intrinsic magnetic properties of the adsorbent additionally enable facile recovery and potential reutilisation in secondary applications, including asphalt production. Collectively, these findings highlight the considerable potential of magnetite nanoparticles as effective and reusable adsorbents for wastewater remediation and support further investigation toward pilot-scale implementation. Full article

The increasing prevalence of multiclass pesticide residues in aquatic environments poses a significant threat to ecosystems and human health. To address this challenge, magnetic Fe₃O₄@Co₅Al-LDH nanoparticles were synthesized as high-performance, easily recoverable catalysts for the peroxymonosulfate (PMS)-mediated degradation of epoxiconazole, atrazine, and metalaxyl. Under optimized conditions (pH 7.0, 35 mg catalyst, and 4.0 mM PMS), the system achieved 100% degradation of the three coexisting pesticides within 15 min. Quenching experiments and electron paramagnetic resonance (EPR) spectroscopy confirmed that SO₄⁻ and ^•OH radicals were the primary reactive species driving the process. Liquid chromatography–mass spectrometry (LC-MS) analysis identified four intermediates for epoxiconazole, three for atrazine, and four for metalaxyl, facilitating the proposal of distinct degradation pathways. The degradation mechanism revealed that electron transfer between Fe/Co and PMS promoted the generation of reactive oxygen species, leading to dechlorination, hydroxylation, and dealkylation of the pesticides transiently adsorbed on the surface of Fe₃O₄@Co₅Al-LDH. In summary, this study demonstrates that Fe₃O₄@Co₅Al-LDH is an easily recoverable, reusable, and cost-effective catalyst for the simultaneous remediation of complex pesticide mixtures in water. Full article

Water resources are essential for human well-being. However, water pollution is a major global problem with significant implications for the environment and public health. To address these challenges, this study presents an integrated perspective on water pollution by correlating pollution sources, transport pathways, exposure routes, and associated risks to human health. The methodology combined a systematic review conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with a bibliometric analysis performed by using VOSviewer version 1.6.19, a software tool for constructing and visualizing bibliometric networks. A total of 332 publications published between 2015 and 2025 were retrieved from the Scopus and Google Scholar databases and met the PRISMA eligibility criteria. The findings indicate that both natural and anthropogenic sources contribute to water contamination, introducing pollutants such as heavy metals, pesticides, pharmaceutical residues, microplastics, and pathogenic microorganisms with potential human health impacts. Bibliometric analysis revealed a transition from conventional water quality assessments toward integrated approaches emphasizing health risks and environmental interactions. The study further identified important knowledge gaps regarding contaminant mixture effects and synergistic toxicity, which remain insufficiently addressed in current scientific and regulatory frameworks. These findings highlight the need for strengthened regulatory strategies, advanced treatment technologies, and evidence-based water governance to support environmental sustainability and public health protection. Full article

Cellulose and chitosan are biopolymers widely used to prepare composites due to their complementary charges and intrinsic biocompatibility. While they are mainly of interest for medical applications, they are also suitable for water remediation. In their native states both biopolymers are non-porous; however, after dissolution and subsequent regeneration they can form porous structures that are better suited for such applications. In this work, cellulose pulp and chitosan were dissolved in an ionic liquid and regenerated in water at different mass ratios to produce hydrogels and their corresponding aerogels. The materials were structurally characterized and evaluated for dye adsorption and antimicrobial performance. Methylene blue and Congo red were selected as cationic and anionic dyes, respectively. The concentrations went from 5 to 80 mg/L in 24 h batch adsorption experiments. Chitosan-rich and intermediate cellulose–chitosan hydrogels preferentially removed Congo red, reaching 27 ± 1 mg/g and 24 ± 1 mg/g at 80 mg/L, respectively; the fully cellulose hydrogel maximized methylene blue uptake, achieving 23 ± 1 mg/g under the same conditions. SEM and XRD analyses revealed a hybrid architecture in which chitosan coats cellulose fibers and becomes more amorphous, while cellulose preserves crystalline domains that act as a rigid, highly porous backbone. Aerogels derived from freeze-dried hydrogels exhibited high porosity and water uptake, together with broad-spectrum antimicrobial activity, achieving bactericidal levels (≥99.9% inhibition) against Staphylococcus aureus for all compositions and against Escherichia coli for selected cellulose–chitosan ratios. These results demonstrate that cellulose–chitosan hydrogels and aerogels function as multifunctional bio-based materials whose supramolecular organization, surface charge distribution, and porosity can be tuned to balance adsorption selectivity and antimicrobial performance for advanced environmental applications. Full article

With rapid urbanization, the generation of municipal solid waste is growing, placing ever-increasing pressure on cities to close, remediate and repurpose landfill sites in environmentally sustainable and climate-adaptive ways. Traditional landfill final covers such as compacted clay and geosynthetic systems are intended to limit infiltration; yet their conceptual designs often fail in performance longevity due to effects such as desiccation, settlement, root intrusion, freeze–thaw cycling and extreme rainfall. Phytocapping, or evapotranspiration/store-and-release cover technology is the use of vegetated soil profiles to provide storage for percolating rainfall, return water to the atmosphere through evapotranspiration and support biologically mediated oxidation of methane. Phytocapping is a green-inclusive nature-based climate adaptation strategy for urban landfill closure. This study explores hydrological performance, methane mitigation, ecological co-benefits, economic feasibility, climate sensitivity, monitoring requirements and regulatory barriers linked to phytocapping systems. Field evidence is strongest in Australia and the United States, especially through ACAP- and A-ACAP-style programs, while evidence from humid tropical, monsoon, freeze–thaw and low-resource urban contexts is comparatively lacking. As reported in published studies, well-designed phytocaps can result in reduced percolation compared to traditional clay caps. Reported publications also mention considerable construction-cost savings, depending on site conditions and design assumptions. Methane-related outcomes vary by measurement method and site context, with studies reporting surface flux reductions, methane oxidation and landfill gas attenuation as distinct performance indicators. These advantages are counter-balanced by design uncertainties that vary from site to site, limited long-term monitoring data, climate transferability concerns, and regulatory systems still firmly anchored in prescriptive low-permeability barriers. This review proposes a policy-oriented analytical framework that bridges the gap between technical performance evidence, urban co-benefits, staged monitoring and performance-based landfill closure regulation. As such, phytocapping should be considered not as a general-purpose substitute for engineered covers, but as a climate-responsive nature-based solution that can complement urban waste servicing infrastructure, ecological restoration and adaptive governance of landfills when properly designed, monitored and regulated. Full article

The remediation of contaminants of emerging concern (CECs) requires innovative, high-efficiency, and sustainable technologies. Here, we investigate active polymeric membranes incorporating TiO₂/ZnO heterojunctions for synergistic sono-enhanced photocatalytic water treatment under both UV and visible-light irradiation. TiO₂/ZnO composites were synthesized and characterized, confirming the formation of type II heterojunctions with tailored optical properties for sunlight-driven photocatalysis. The catalysts were integrated into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) matrixes using electrospinning (ES) and thermally induced phase separation (TIPS). ES membranes, specifically the ZnO-rich heterojunction within a PVDF-TrFE matrix (3T-7Z@TrFE ES), achieved the highest performance toward ciprofloxacin (CIP) degradation, reaching 71 and 57% under UV and visible light, respectively. The hybridization of the method by coupling ultrasound induced significant synergistic effects, with relative enhancement factors up to 1.38. Furthermore, the sono-enhanced photocatalytic pathway shifted the degradation mechanism towards the early fragmentation of the harmful piperazine ring, yielding a more sustainable degradation process. In addition, the composite membranes showed selective antibacterial activity against S. aureus, making this a multifunctional platform able not only to degrade CECs but also to mitigate membrane fouling. Overall, this work demonstrates the potential of tailored heterojunctions and composite membranes as sustainable platforms for the remediation of recalcitrant CECs in water, highlighting the synergy between photoactivity, piezoelectricity, and mechanistic control. Full article

With the growing emphasis on environmental sustainability, the proper treatment of industrial wastewater and the protection of groundwater resources have become pressing global concerns. Congo red (CR), a widely used azo dye, enters water bodies via wastewater discharge, posing persistent ecological risks to surface and groundwater systems. Adsorption, as a direct and sustainable remediation approach, necessitates the development of high-performance adsorbents to inhibit CR migration into groundwater. In this study, a Fe₂O₃/γ-Al₂O₃ composite was synthesized via sol-gel method for efficient CR adsorption, thereby mitigating groundwater contamination risk. The composite exhibited a high specific surface area (246.22 m²/g) and a maximum adsorption capacity of 1027.72 mg/g. Adsorption behavior followed the pseudo-second-order kinetic and Langmuir isotherm models, consistent with chemisorption-driven monolayer adsorption. The Weber–Morris intraparticle diffusion model confirmed rapid initial surface adsorption, beneficial for practical groundwater remediation. pH-dependent adsorption efficiency further indicated the role of electrostatic interactions, informing process optimization under varying groundwater chemistries. DFT calculations demonstrated that Fe₂O₃/γ-Al₂O₃ possesses a higher adsorption affinity for CR than γ-Al₂O₃. Collectively, Fe₂O₃/γ-Al₂O₃ shows strong potential as a novel, efficient adsorbent for CR interception and groundwater quality protection. Full article

The contamination of aquatic environments by cadmium and other toxic heavy metals represents a major environmental concern requiring efficient and operationally sustainable remediation strategies. In this work, iron oxide materials were synthesized through a microwave-assisted hydrothermal method and evaluated for Cd(II) removal from aqueous systems. Different precursor compositions and organic additives were initially screened in order to identify the most suitable adsorbent formulation. The selected Fe-Tart material was characterized by FTIR, SEM-EDS, and XRD analyses, revealing hydroxylated and poorly crystalline iron oxide structures with heterogeneous surface organization. Batch adsorption experiments were performed under controlled conditions to investigate the influence of pH and equilibrium adsorption behavior, while adsorption data were analyzed using Langmuir and Freundlich isotherm models. Cd(II) uptake showed strong pH dependence, with adsorption progressively increasing from acidic to near-neutral conditions and reaching approximately 80% removal at pH 7–8. The Langmuir model provided the best fitting results (R² = 0.988), suggesting preferential occupation of energetically comparable surface sites with a maximum adsorption capacity of 6.51 mg g⁻¹. The adsorption behavior was interpreted within a pH-dependent surface complexation framework involving hydroxylated iron oxide surfaces. Although the adsorption capacity remained lower than that reported for some highly engineered adsorbents, the results indicate that microwave-assisted synthesis may provide a relatively simple and rapid route for preparing iron oxide-based materials potentially applicable to water remediation systems. Full article

Hexavalent chromium (Cr (VI)) contamination of water resources constitutes a major environmental and public health issue due to its high toxicity, mobility, and carcinogenic properties. This review examines recent advances in Cr (VI) removal technologies from water and wastewater, with emphasis on membrane-based separation processes and adsorption approaches. Conventional treatment methods, including chemical precipitation, ion exchange (IX), electrocoagulation (EC), electrodeionization (EDΙ), bioremediation, and photocatalysis, are comparatively discussed in terms of removal efficiency, operational limitations, and applicability. In parallel, sustainable adsorbent materials derived from biomass and agricultural waste are evaluated as environmentally friendly and cost-effective alternatives for chromium removal. The role of functional groups, adsorption mechanisms, and redox interactions involved in Cr (VI) reduction and immobilization is also analyzed. Attention is given to membrane technologies, such as reverse osmosis (RO), nanofiltration (NF), electrodialysis (ED), and ultrafiltration (UF) after surface modification with the incorporation of nanomaterials and/or the application of Layer-by-Layer (LBL) assembly techniques, which enhance selectivity, permeability, and antifouling behavior. The reviewed studies demonstrate that advanced membrane systems and bio-based adsorbents can achieve high chromium removal efficiencies while supporting sustainable water treatment practices. Overall, the combination of membrane technologies with functionalized materials represents a promising direction for the development of efficient and environmentally sustainable Cr (VI) remediation systems capable of meeting increasingly strict regulatory limits. Full article

This systematic review evaluates the application of green-synthesized nanoparticles for the removal of uranium (U) and thorium (Th) from contaminated water sources. The study focuses on the synthesis methods, adsorption performance, operational parameters, and environmental implications associated with these nanomaterials. Following PRISMA guidelines, studies published between 2015 and 2025 were identified through searches conducted in the Scopus and Web of Science databases. The review highlights the predominance of iron-based nanoparticles, biochar-derived materials, and biopolymer-based composites, many of which demonstrated removal efficiencies exceeding 90% and high adsorption capacities for U (VI) and Th (IV). Key factors influencing performance include solution pH, adsorbent dosage, contaminant concentration, and contact time. The review also examines adsorption mechanisms, regeneration potential, scalability challenges, and concerns related to environmental safety and nanoparticle recovery. Although the reported results demonstrate significant potential for radionuclide remediation, most studies remain limited to laboratory-scale experiments using synthetic water. This review synthesizes current knowledge, identifies existing research gaps, and discusses future directions required to support the practical implementation of green nanotechnologies for sustainable water treatment. Full article