Search Results (228)

Diffuse pollution from agricultural runoff, characterized by intermittent discharges of complex contaminant mixtures, including nutrients, pesticides, and heavy metals (HMs), poses a persistent threat to global water quality. Conventional “end-of-pipe” strategies often fail to address these decentralized, nonpoint sources. This review examines the evolution of Permeable Reactive Barriers (PRBs) from static, abiotic filters into modern Permeable Reactive Bio-Barriers (PRBBs), engineered as dynamic, fixed-bed biofilm reactors. A key advancement in PRBB efficacy is the exploitation of biofilm plasticity, particularly in response to coexistence with organic and inorganic pollutants. While heavy metals are traditionally viewed as inhibitors, this review synthesizes evidence showing that subinhibitory HM levels can act as structural and functional drivers. These metals induce the upregulation of Extracellular Polymeric Substances (EPSs), creating a “protective shield” that sequesters metals and confers functional resilience on the microbial consortia responsible for nutrient removal and pesticide biodegradation. The review analyzes contaminant removal mechanisms, highlighting the bio-chemo synergy between reactive media and biofilms, and proposes a classification framework based on target contaminants, media, and technological integration. Significant focus is placed on emerging hybrid multi-media systems designed to protect the microbial community from toxic metal shocks, alongside the integration of artificial intelligence for predictive control. While challenges in hydraulic sustainability and field validation remain, PRBBs represent a compact, low-energy, and scalable ecotechnology. PRBBs offer a strategically targeted solution within the Nature-Based Solutions toolkit for building resilient protection of aquatic ecosystems at the critical land-water interface. Full article

In recent decades, triazine herbicides (THs), one of the most widely used agrochemicals, have been extensively applied to enhance crop yields. However, their persistent nature and high mobility have resulted in pervasive contamination of aquatic ecosystems, posing significant risks to non-target organisms and human health through bioaccumulation and endocrine disruption. Addressing THs pollution in water bodies has thus emerged as a critical environmental challenge. This study reviews the efficacy of biochar, a carbon-rich material derived from biomass pyrolysis, for TH removal due to its high surface area, hierarchical porosity, and tunable surface functionality. The maximum reported adsorption capacities are up to 260.5 mg·g⁻¹; with degradation efficiencies, they can exceed 99.5% in advanced oxidation systems. Mechanistic investigations reveal that TH removal primarily involves π–π interactions, hydrogen bonding, pore filling, and electrostatic attraction during adsorption, while degradation proceeds via radical pathways (e.g., •OH, SO₄^•−) and nonradical routes (e.g., ¹O₂, direct electron transfer) in processes such as persulfate activation, photocatalysis, and Fenton-like reactions. By analyzing degradation intermediates and pathways, this review underscores the necessity of coupling adsorption with advanced oxidation to achieve complete mineralization and mitigate secondary ecological risks. Furthermore, it emphasizes the importance of tailoring biochar’s physicochemical properties through feedstock selection, pyrolysis conditions, and chemical modifications to optimize THs’ removal performance. This work advocates for the integration of biochar-based technologies into sustainable water treatment frameworks, aligning with carbon neutrality goals and circular economy principles. Future research should prioritize scalable synthesis methods, long-term stability assessments, and field-scale validations to translate laboratory insights into practical solutions for safeguarding global water resources. However, realizing this potential requires that we overcome challenges related to matrix interference, catalyst deactivation, and incomplete mineralization, which are often overlooked in laboratory-scale studies. Full article

Fracturing flowback fluid is a complex wastewater generated during oil extraction, characterized by high concentrations of organic matter, suspended solids, salts, and various chemical additives, posing substantial risks to both surface water and groundwater if discharged directly. This study investigated the treatment of simulated fracturing flowback fluid prepared with guar gum using low-temperature plasma coupled with hydrogen peroxide technology. The degradation efficacy and preliminary mechanism of the combined system on organic pollutants were explored. Through a systematic optimization of operational parameters in the laboratory, the optimal treatment conditions were determined as a discharge voltage of 18 kV, a hydrogen peroxide addition of 5%, an initial pH of 11, and a treatment time of 110 min. Under these conditions, the synergistic system achieved 89.59 percent degradation of organic pollutants and 92.96 percent chemical oxygen demand removal. The results revealed that the combined action induced breakage of guar gum polymer chains, thereby enhancing degradation efficiency while effectively controlling fluid viscosity. This technology establishes a practical treatment approach for simulated fracturing flowback fluids containing guar gum, thereby facilitating better waste management in the energy sector. Full article

Driven by rapid global urbanization and expanding urban footprints, air pollution, particularly from industrial emissions and vehicular exhaust, has intensified, with rising concentrations of inhalable particulate matter (PM) posing direct threats to public health. To address this challenge, we conducted field measurements of ambient PM concentrations across diverse urban plant communities and quantitatively compared their capacity to mitigate four key size-fractionated pollutants: total suspended particles (TSPs), PM₁₀, PM_2.5, and PM₁. Our objective was to identify the most effective plant community type for PM abatement in urban settings. Results demonstrate that: (1) evergreen broad-leaved forests exhibit the highest overall PM removal efficiency among all studied communities; (2) removal efficacy declines markedly with decreasing particle size, indicating limited capacity to capture ultrafine particles (e.g., PM₁); and (3) seasonal performance peaks in summer, especially for deciduous broad-leaved forests attributable to maximal leaf area index, enhanced stomatal activity, and favorable meteorological conditions. By rigorously evaluating species composition, canopy structure, and seasonal dynamics, this study provides empirically grounded guidance for evidence-based urban greening strategies aimed at optimizing airborne particulate mitigation worldwide. Full article

To efficiently remove oxytetracycline (OTC) pollution from water bodies, this study utilized fava bean straw as a precursor to synthesize iron-nitrogen (Fe/N) co-doped biochar via pyrolysis. By regulating the synthesis ratio of iron and nitrogen, the material’s adsorption performance was optimized. The adsorption characteristics and mechanisms of OTC were systematically investigated. The findings reveal that when the proportion of iron to nitrogen is set at 1:3, the adsorption efficacy reaches its peak. Moreover, this material demonstrates outstanding reusability characteristics. The outcomes of kinetic fitting suggest that the adsorption procedure adheres to the pseudo-second-order kinetic model (R² = 0.967), primarily characterized by chemisorption. The isothermal adsorption data better fit the Langmuir model (R² = 0.9984), with a theoretically attainable upper-limit adsorption capacity reaching 666.13 mg/g. This signifies the occurrence of monolayer adsorption, while the adsorption procedure constitutes an endothermic reaction. Based on characterization and mechanistic analysis, it can be concluded that the adsorption mechanism of Fe1N3KBC on OTC mainly involves π-π stacking interactions and chelation reactions. The Fe/N co-doped biochar prepared in this present research features readily available raw materials and a simple preparation process, combining high adsorption efficiency with excellent stability. It provides a novel technical paradigm for developing environmentally friendly adsorbents to address antibiotic pollution in water bodies. Full article

Achieving simultaneous control over total carbon emissions and intensity is essential for China’s dual carbon goals. Using panel data from 1235 listed manufacturing firms (2015–2022), we construct a composite index to measure dual carbon control and investigate how data elements influence corporate carbon performance from an industry heterogeneity perspective. The main findings are as follows. (1) Data elements significantly enhance dual carbon control, with effects concentrated in high-pollution sectors, particularly metallurgy and mineral products, while remaining insignificant in low-pollution industries. (2) Mechanisms differ across industry types: capacity utilization drives improvements in high-pollution industries, whereas green technology innovation matters in low-pollution sectors such as agro-processing and textiles. (3) ESG disclosure and green credit subsidies amplify these effects, though with varying efficacy. Policymakers should adopt differentiated strategies including removing structural barriers to green innovation in high-pollution industries and activating capacity utilization through monitoring standards and technology markets in low-pollution sectors. A tailored policy framework is essential to realize the full potential of data elements in advancing China’s dual carbon goals. Full article

Stormwater runoff represents a significant vector for the transport of organic pollutants and pathogens into aquatic ecosystems, posing serious environmental and public health risks. Although extensively employed for bank stabilization, traditional gabion structures demonstrate constrained efficacy in pollutant removal. In this study, an enhanced ecological gabion (EG) system was developed by integrating a stratified configuration of functional fillers (ceramsite, maifanite, and biochar) with vegetation (Iris germanica). This design leverages synergistic effects to enhance the concurrent removal of dissolved organic matter (DOM), particulate organic matter (POM), and fecal indicator bacteria (FIB) from simulated stormwater. The system was evaluated in continuous flow experiments through comparison with a traditional gravel gabion (TG). Results showed that, compared with the TG, the EG exhibited markedly enhanced removal performance, with chemical oxygen demand (COD), NH₄⁺–N, and TN removal efficiencies being approximately 2.48, 3.68, and 3.56 times those of the TG, respectively. In addition, the EG exhibited significantly higher removal efficiencies for both particulate organic carbon (POC) and dissolved organic carbon (DOC) than the TG, with increases of 329% and 137%, respectively. Fluorescence spectroscopy and particle size distribution analyses revealed that the EG effectively transformed and removed diverse DOM components and fine particulates. The stratified filler media synergistically enhanced pollutant retention, with biochar serving as the primary agent for nutrient and pathogen adsorption. These findings demonstrate the viability of the EG as an integrated, eco-friendly solution for enhanced stormwater purification in riparian zones, providing a compact and multifunctional alternative to conventional end-of-pipe systems. Full article

Bioaugmentation, defined as the strategic incorporation of specifically selected microbial biomass into contaminated environments, can significantly enhance the biodegradation of pollutants and is extensively employed in soil bioremediation efforts. A multistep screening process was applied to develop an autochthonous microbial consortium, including (i) hydrocarbonoclastic strain isolation from soil chronically contaminated with petroleum hydrocarbons, (ii) bacterial selection according to genomic and functional traits, and (iii) consortium validation in the native contaminated soil through microcosm experiments. The selection of strains with the ability to degrade alkanes and aromatic hydrocarbons on synthetic media was further supported by genomic analysis, delivering a consortium with complementary degradative properties. The outcomes of the microcosm experiments corroborated the efficacy of the selected indigenous consortium, demonstrating that the combination of Acinetobacter guillouiae, A. radioresistens, and Pseudomonas zarinae as an inoculum in the bioaugmentation strategy was successful in achieving the removal of up to 26% and 76% of linear and polycyclic aromatic hydrocarbons, respectively, thereby effectively addressing areas where natural attenuation was insufficient. Full article

Water represents the fundamental source of life for all human and animal populations; however, its consumption has become increasingly hazardous due to high levels of pollution. Modern agricultural practices rely heavily on pesticides, which significantly contribute to water contamination and imbalances in aquatic ecosystems. Moreover, another critical category of pollutants consists of pathogenic bacteria that proliferate in aquatic environments, mainly originating from hospital and urban wastewater because of human activity. Considering these major environmental and health challenges, the present study aims to develop an optimized method for water treatment by synthesizing magnetic silica-based aerogels using a microfluidic vortex chip and systematically varying synthesis parameters to enhance material performance. The physicochemical properties of the aerogels were characterized using XRD, FTIR, SEM, EDS, and BET. The pesticide adsorption capacity of the materials was evaluated using FT-ICR HR-MS analysis, which demonstrated the high efficiency of the aerogels in removing a complex mixture of pesticides. In parallel, antimicrobial efficacy was assessed against E. faecalis, E. coli, and P. aeruginosa isolated from surface water, hospital wastewater, and the influent of a well-known wastewater treatment plant in Bucharest, as well as against ATCC reference strains. Additionally, the study investigated the biocompatibility and biological responses of magnetic aerogels using MTT assays, nitric oxide production, lactate dehydrogenase release, intracellular ROS levels, and quantification of total protein, malondialdehyde, and reduced glutathione in HaCaT and HEK293 cell lines. The results confirm the efficiency and application potential of the developed materials and emphasize the importance of optimizing synthesis to achieve high-performance aerogels for effective decontamination of polluted waters. Full article

This study presents a waste-valorization strategy by developing calcined natural shell particles (CNSP) derived from waste oyster shells as an efficient tribocatalyst for degrading high-concentration organic pollutants, a challenge for which conventional photocatalytic approaches are hindered by light shielding. The CNSP catalyst, confirmed as calcite CaCO₃ with low surface area and stable crystalline structure, demonstrated exceptional efficacy in degrading Rhodamine B (RhB) solutions across a wide concentration range (50–300 mg/L) under mechanical friction, achieving 99% removal of 50 mg/L RhB in 1 h and 300 mg/L RhB in 18 h with a 0.5 g catalyst. This catalyst maintained a degradation efficiency of over 95% in a continuous six-cycle process. Mechanistic studies revealed that the tribocatalytic process generates reactive oxygen species (ROS), primarily hydroxyl ($•\mathrm{O}\mathrm{H}$) and superoxide ($•{{\mathrm{O}}_2}^{-}$) radicals, which drive the decomposition of dye molecules. Electron paramagnetic resonance (EPR) spectroscopy directly confirmed the generation of these radicals. These findings establish CNSP as a promising, low-cost, and environmentally benign catalyst for wastewater treatment. This work not only provides a novel strategy for high-concentration dye removal but also reduces the environmental burden of aquaculture shell disposal. Further work is needed to evaluate its performance in real industrial effluents and with mixed pollutants. Full article

Photocatalytic processes have emerged as an efficacious strategy for the removal of organic pollutants from wastewater. In the present investigation, a BiVO₄ nanorod supported on Bi₂O₂S nanosheet catalyst (referred to as BiVO₄/Bi₂O₂S) was meticulously synthesized via a straightforward synthetic approach, aimed explicitly at the photodegradation of tetracycline (TC). The optimized BiVO₄/Bi₂O₂S composite, with a theoretical weight ratio of BiVO₄ to Bi₂O₂S at 2:1 (designated as 2BVO/BOS), demonstrated a significant improvement in tetracycline degradation efficiency, achieving up to 82.9% under visible light irradiation for 90 min. This result stands in stark contrast to the relatively low degradation rates of 42.9% and 50.7% observed for pure BiVO₄ and Bi₂O₂S, respectively. Furthermore, the apparent reaction rate of 2BVO/BOS (approximately 0.01894 min⁻¹) was 3.19-fold and 2.66-fold higher than those of BiVO₄ (0.00594 min⁻¹) and Bi₂O₂S (0.00713 min⁻¹), respectively. This significant improvement in photocatalytic efficacy can be ascribed to the composite’s superior capacity for visible light absorption, as well as its remarkable proficiency in charge carrier separation and transfer. Comprehensive experimental analyses, corroborated by extensive characterization techniques, revealed the formation of a distinctive S-scheme charge transfer mechanism at the interface between BiVO₄ and Bi₂O₂S. This mechanism effectively suppresses charge recombination and optimizes the redox potentials of the photogenerated carriers, thereby enhancing the overall photocatalytic performance. The current study underscores the remarkable potential and promising application of BiVO₄/Bi₂O₂S composite in the realm of wastewater treatment. Full article

Urban pollution—especially SO₂ and particulate matter—rapidly darkens and degrades outdoor-exposed wall paintings due to soiling. Laser cleaning has emerged as a cutting-edge solution, offering selective removal of contaminant layers while preserving the integrity of the underlying materials. This study explores the performance of a 355 nm Nd:YAG laser in cleaning artificially aged paint mock-ups coated with real diesel soot and exposed to an accelerated aging test with SO₂ exposure. Traditional mineral pigments—silicates (Egyptian blue, ultramarine blue, and green earth), oxides (chromium green, mars red), and a sulphide (cinnabar)—were applied following fresco and secco (egg yolk) techniques, allowing researchers to uncover how pigment chemistry and binders affect laser sensitivity. Damage thresholds were first determined for each pigment and painting technique via digital photography, stereomicroscopy, and colour spectrophotometry. Cleaning efficacy was then assessed by stereomicroscopy, colour spectrophotometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The results revealed clear patterns: silicate pigments exhibit stability under laser irradiation, enabling safe cleaning, whereas mars red and cinnabar remain highly sensitive regardless of the technique. Generally, secco paintings were more susceptible to laser radiation than fresco. These finding provide practical guidance for optimising laser-cleaning protocols while safeguarding the delicate surfaces of historic wall paintings. Full article

Mn⁴⁺-activated fluoride phosphors possess outstanding luminescent properties, making them highly suitable for applications in lighting and display technologies. However, the synthesis of such phosphors generally requires the use of large amounts of highly toxic aqueous HF, leading to serious environmental pollution. To eliminate the use of hazardous HF solution, a low-temperature molten salt method employing NH₄HF₂ was developed to synthesize the narrow-band red emitter Cs₂GeF₆: Mn⁴⁺ phosphor. Following the reaction, the product was washed with a dilute H₂O₂ solution to remove residual NH₄HF₂ and other impurities. The phase purity and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, and the luminescence properties were examined via photoluminescence (PL) spectroscopy. The obtained phosphors exhibit bright red emission characteristics of Mn⁴⁺ under blue-violet excitation. Among them, Cs₂GeF₆: 0.08 Mn⁴⁺ shows the highest emission intensity, with an internal quantum efficiency (IQE) of 78%. A white light-emitting diode (WLED) fabricated by combining this phosphor with a blue chip and commercial Y₃Al₅O₁₂: Ce³⁺ (YAG) phosphor achieved a high luminous efficacy (LE) of ~146 lm/W, a correlated color temperature (CCT) of ~4396 K, and a color rendering index (Ra) of ~83, alongside excellent operational color stability. Full article

Black-odorous water pollution presents a serious threat to aquatic ecosystems and severely hinders the sustainable development of the ecological environment, as conventional remediation technologies often fall short in achieving the simultaneous removal of multiple pollutants. In this study, a novel composite remediation agent was developed by integrating microbial active components with modified clay minerals—sodium-modified zeolite (Na-Z) and magnesium–aluminum–lanthanum layered ternary hydroxides loaded onto sulfuric acid-modified bentonite (Mg-Al-La-LTHs@SBt)—through gel-embedding immobilization. This integrated system enabled the synergistic remediation of both overlying water and sediment pollutants. The modified clay minerals exhibited strong adsorption capacity for nitrogen and phosphorus compounds in the overlying water. Under 25 °C conditions, the composite agent achieved removal efficiencies of 58.14% for ammonium nitrogen (NH₄⁺-N) and 88.89% for total phosphorus (TP) while significantly reducing sedimentary organic matter and acid volatile sulfide (AVS). Notably, the agent retained substantial remediation efficacy even under low-temperature conditions (5 °C). High-throughput microbial community analysis revealed that the treatment enriched beneficial phyla (e.g., Proteobacteria) and beneficial genera (e.g., Thiobacillus) and suppressed sulfate-reducing groups (e.g., Desulfobacterota), promoting favorable nitrogen and sulfur transformations. These results provide a robust material and methodological basis for efficient, synergistic restoration of black-odorous water and the sustainable development of water resources. Full article

To mitigate the risks associated with production wastewater from water treatment plants, this study evaluated the effectiveness of nanofiltration (NF) and a hybrid ceramic membrane–nanofiltration (CM–NF) process in removing natural organic matter (NOM) and Ca²⁺. A comprehensive analysis of changes in specific flux and fouling resistance of the NF membrane, combined with scanning electron microscopy (SEM) observations, provided deeper insight into membrane fouling behavior. The results show that the CM–NF process achieved average removal rates of 95.60% for DOC, 98.55% for UV₂₅₄, 34.50% for conductivity, and 50.71% for Ca²⁺. These values represent improvements of 4.70%, 1.40%, 16.37%, and 10.36%, respectively, compared to the standalone NF process. Furthermore, CM pretreatment consistently optimized the performance of the nanofiltration system. After continuous operation, the average specific membrane flux of the CM–NF system reached 0.715, 0.67, and 0.61 under varying pollutant concentrations—increases of 10.9%, 19.6%, and 17.3% over the standalone NF system—confirming a significant improvement in permeate flux. Under continuous operation, the average degree of irreversible fouling was markedly reduced across different pollutant concentrations—decreasing from 9.2%, 17.6%, and 23.6% for the standalone NF system to 8.9%, 15.6%, and 10.9% for the CM–NF system, which clearly demonstrates the efficacy of CM pretreatment in controlling irreversible fouling. SEM observations further corroborated that CM pretreatment effectively alleviated fouling on the NF membrane surface. Additionally, higher Ca²⁺ concentrations were found to contribute to reduced membrane fouling and enhance flux performance. Full article