Search Results (366)

Halide perovskites have many advantages in environmental remediation. The photocatalytic performance of halide perovskites is often hindered by low specific surface area and rapid photogenerated carrier recombination. The aim of this work is to prepare a green, novel photocatalyst in the form of biochar-anchored Cs₃Bi₂Br₉ perovskite composites. The rose-petal-derived biomass carbon (RC) provides adsorption sites and high electrical conductivity, while the perovskite Cs₃Bi₂Br₉ can efficiently capture visible right and degrade pollutants, and the reciprocal effect can enhance the photocatalytic efficiency of the composite. The results of scanning electron microscopy (SEM) showed the Cs₃Bi₂Br₉ particles were loaded on the surface of RC. Compared with bare Cs₃Bi₂Br₉, Cs₃Bi₂Br₉/RC composite has a more perfect structure, higher specific surface area, enhanced ability to absorb visible light, and reduced bandgap value. As visible-light-driven photocatalysts, the prepared Cs₃Bi₂Br₉/RC composites can enhance the removal efficiency of Rhodamine B. The Cs₃Bi₂Br₉/RC–0.2 composite displays the highest degradation efficiencies for RhB (10 mg/L), reaching 98% within 60 min. And the rate constant (k) is 1.9 times that of bare Cs₃Bi₂Br₉. The results of electrochemical impedance spectroscopy (EIS) show that the interaction between RC and Cs₃Bi₂Br₉ speeds up charge carrier separation and transfer. During photocatalytic process, holes (h⁺) and superoxide radicals (·O₂⁻) played major roles. The composites also showed excellent stability. It is meaningful to deal with a large number of withered rose petals to make them high-value products. This work not only provides a guideline for the construction of perovskite composites materials but also shows the promising prospects of biochar composites in deep treatment for contaminated water. Full article

Nitrate pollution in groundwater poses severe threats to ecosystems and human health, making the electrochemical nitrate reduction reaction (NO₃RR) a promising remediation technology. Conductive metal–organic frameworks (cMOFs) with π-d conjugation, dispersed active sites, and tunable structures are ideal candidates for electrocatalysis. Herein, we synthesized a series of cMOFs (M₃(HHTP)₂, M = Fe, Zn, Cu, Co, Ni) via conjugated coordination between hexahydroxytriphenylene (HHTP) ligands and metal ions and systematically investigated their NO₃RR performance. Electrochemical tests revealed that Fe₃(HHTP)₂ exhibits superior catalytic performance for nitrate reduction, achieving a high NH₃ selectivity of 99.5% and a yield rate of 676.4 mg·g_cat⁻¹·h⁻¹ at −1.0 V vs. RHE (reversible hydrogen electrode), along with excellent cyclic and structural stability. In situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy identified key intermediates (*NO₂, *NH₂OH) and proposed the reaction pathway: NO₃⁻ → *NO₃ → *NO₂ → *NO → *NOH → *NH₂OH → *NH₂ → *NH₃. DFT calculations revealed that Fe center exhibited a lower energy barrier for NO₃RR compared to other metal ions (Zn, Cu, Co, Ni). This study demonstrates the significant potential of Fe₃(HHTP)₂ for efficient NO₃RR and provides new insights into the structure-function relationship of cMOF-based electrocatalysts. Full article

The fish liver, as the main detoxification organ, is highly susceptible to xenobiotic exposure, often resulting in various hepatopathies. The cytochrome P450 system plays a central role in xenobiotic metabolism, with cytochrome P450 reductase (CYPOR) supplying the electrons required for CYP enzyme activity. This study aimed to evaluate the relationship between the ecological state of a reservoir and fish health, including CYPOR levels, through hematological, bacteriological, and histological analyses. Samples of water and fish were collected from 12 littoral sites of Lake Ladoga. A total of 1360 specimens of fish from carp (Cyprinidae) and perch (Percidae) families were examined. For histological examination and CYPOR level determination, we selected 40 specimens using a blind randomization method. This sample size was sufficient for statistical analyses. Hematological smears were stained with azure eosin; bacteriological cultures were grown on multiple media; liver samples were stained with hematoxylin and eosin and Sudan III. CYPOR levels in liver homogenates were measured by ELISA-test. Physical and hydrochemical analyses indicated a high pollution level in the littoral zones. Isolated bacterial species were non-pathogenic but exhibited broad antibiotic resistance. Hematological evaluation revealed erythrocyte vacuolization and anisocytosis. Histological analysis showed marked fatty degeneration in hepatocytes, indicating toxic damage. CYPOR concentrations ranged from 0.3–0.4 ng/mL in healthy fish to 5–6 ng/mL in exposed specimens, showing strong correlation between environmental influence and enzyme activity. These findings demonstrate the potential of CYPOR as a sensitive biomarker for biomonitoring programs. The integrated methodological approach provides a model for assessing aquatic ecosystem health and identifying zones requiring priority remediation. Full article

Soil heavy metal contamination poses significant risks to ecological safety and human health, particularly in rapidly industrializing cities. Effectively identifying pollution sources is crucial for risk management and remediation. GIS coupled with data mining techniques, provide a powerful tool for quantifying and visualizing these sources. This study investigates the concentration, spatial distribution, and sources of heavy metals in urban soils of Bengbu City, an industrial and transportation hub in eastern China. A total of 139 surface soil samples from the urban core were analyzed for nine heavy metals. Using integrated GIS and PCA-APCS-MLR data mining techniques, we systematically determined their contamination characteristics and apportioned sources. The results identified widespread Hg enrichment, with concentrations exceeding background levels at all sampling sites, and a Cd exceedance rate of 28.06%, leading to a moderate ecological risk level overall. Spatial patterns revealed significant heterogeneity. Quantitative source apportionment identified four primary sources: industrial source (37.1%), which was the dominant origin of Cr, Cu, and Ni, primarily associated with precision manufacturing and metallurgical activities; mixed source (26.7%) governing the distribution of Mn, As, and Hg, mainly from coal combustion and the natural geological background; traffic source (22.3%) significantly contributing to Pb and Zn; and a specific cadmium source (13.9%) potentially originating from non-ferrous metal smelting, electroplating, and agricultural activities. These findings provide a critical scientific basis for targeted pollution control and sustainable land-use management in analogous industrial cities. Full article

No method to assess the risks of petroleum hydrocarbon pollutants C6–C9 in soils on construction land in China has been established. At one decommissioned petroleum refinery site in northwestern China, we performed an innovative tier 3 risk assessment method using carbon fraction proportions. Using HJ 25.3 guidelines, the risk-screening value for soil contamination of land by petroleum hydrocarbons was 192 mg kg⁻¹ for industrial land use. However, based on site-specific parameters, this value was 226 mg kg⁻¹, with a corresponding contaminated soil volume of 381,904 m³. A tier 3 risk assessment incorporating carbon fraction proportions and site-specific parameters yielded a risk control value of 2370 mg kg⁻¹ and reduced the soil volume requiring decontamination to 87,047 m³, potentially saving CNY 324 million (~USD 45.5 million as of November 2025) in remediation costs. Therefore, implementing a tier 3 risk assessment for C6–C9 pollutants can optimize remediation strategies and enhance the precision and scientific rigor of petroleum hydrocarbon-contaminated soil remediation. Full article

Urban areas often suffer from enduring environmental issues, including flooding, biodiversity loss, heat island effects, and air and soil pollution. The Miyawaki method of afforestation, characterized by dense planting of native species on remediated soil, has been proposed as a rapid, nature-based solution for restoring urban ecological function. This study aims to evaluate early-stage changes in soil health following Miyawaki-style microforest establishment in formerly redlined neighborhoods in Elizabeth, New Jersey. Specifically, it investigates whether this method improves soil permeability, carbon content, and microbial activity within the first three years of planting. Three microforests aged one, two, and three years were assessed using a chronosequence approach. At each site, soil samples from within the microforest and adjacent untreated urban soil (control) were compared. Analyses included physical (porosity, dry density, void ratio), chemical (total carbon), and biological (microbial respiration, biomass, metabolic rate, carbon use efficiency) assessments. Soil permeability was estimated via the Kozeny–Carman equation. Microforest soils showed significantly greater porosity (p = 0.015), higher void ratios (p = 0.009), and reduced compaction compared to controls. Soil permeability improved dramatically, with factors ranging from 5.99 to 52.27. Total carbon content increased with forest age, reaching 2.0 mg C/g in the oldest site (p < 0.001). Microbial metabolic rate rose by up to 287.5% (p = 0.009), while carbon use efficiency also improved, particularly in the older microforests. Within just one to three years, Miyawaki microforests significantly enhanced both the physical and biological properties of degraded urban soils, signaling rapid restoration of soil function and the early return of ecosystem services. Full article

As China’s industrialization progresses, the transformation of site properties across various regions has become increasingly common. Concurrently, with the relocation and market exit of some enterprises, the land occupied by the original factory sites has been developed for other uses. This study provides a comprehensive evaluation of soil and groundwater contamination levels and the associated ecological and health risks in abandoned industrial lands. The investigation focused on analyzing heavy metal and polycyclic aromatic hydrocarbon (PAH) contamination using various assessment methods, including the single-factor pollution index, Nemerow composite pollution index, and potential ecological risk index. These methods were used to assess the contamination levels of 11 heavy metals in both soil and groundwater. Additionally, health risk assessments for PAHs were conducted using the Incremental Lifetime Cancer Risk (ILCR) and Carcinogenic Risk (CR) models, considering both direct and indirect exposure pathways. The results indicated that the average concentration of each heavy metal in the soil did not exceed the screening thresholds, with all Nemerow index values falling below 1, suggesting that the site is not significantly polluted. Ecological risk assessment further revealed that most heavy metals posed minor risks, while some localized areas showed slight enrichment. Health risk assessments for PAHs indicated that, although the risks for both adults and children were within acceptable limits, the ingestion pathway for children showed a slightly higher risk compared to adults. The groundwater quality met Class IV standards, indicating no significant pollution. These findings provide data support and reference for future land-use planning, environmental management, and remediation strategies for abandoned industrial sites. Full article

A cobalt-containing zeolitic imidazolate framework (ZIF-67) was carbonized by different routes to composite materials (cZIFs) composed of metallic Co, Co₃O₄, and N-doped carbonaceous phase. The effect of the carbonization procedure on the water pollutant removal properties of cZIFs was studied. Higher temperature and prolonged thermal treatment resulted in more uniform particle size distribution (as determined by nanoparticle tracking analysis, NTA) and surface charge lowering (as determined by zeta potential measurements). Surface-governed environmental applications of prepared cZIFs were tested using physical (adsorption) and electrochemical methods for dye degradation. Targeted dyes were methylene blue (MB) and methyl orange (MO), chosen as model compounds to establish the specificity of selected remediation procedures. Electrodegradation was initiated via an intermediate reactive oxygen species formed during oxygen reduction reaction (ORR) on cZIFs serving as electrocatalysts. The adsorption test showed relatively uniform adsorption sites at the surface of cZIFs, reaching a removal of over 70 mg/g for both dyes while governed by pseudo-first-order kinetics favored by higher mesoporosity. In the electro-assisted degradation process, cZIF samples demonstrated impressive efficiency, achieving almost complete degradation of MB and MO within 4.5 h. Detailed analysis of energy consumption in the degradation process enabled the calculation of the current conversion efficiency index and the amount of charge associated with O₂^•−/^•OH generation, normalized by the quantity of removed dye, for tested materials. Here, the proposed method will assist similar research studies on the removal of organic water pollutants to discriminate among electrode materials and procedures based on energy efficiency. Full article

The Semipalatinsk Test Site (STS), one of the most heavily contaminated nuclear test sites globally, presents critical challenges for ecological monitoring and restoration due to long-term radioactive pollution and soil degradation. This study applied the Remote Sensing Ecological Index (RSEI) model to systematically evaluate the spatiotemporal changes in ecological quality at STS from 2003 to 2023. The RSEI model integrated multi-indicator data, including NDVI (Normalized Difference Vegetation Index), LST (Land Surface Temperature), WET (Wetness), and NDBSI (Normalized Difference Built-up and Soil Index), enabling a comprehensive assessment of ecological dynamics. Results demonstrated a significant improvement in ecological quality, with the RSEI increasing by 29.59% (from 0.345 in 2003 to 0.447 in 2023). PCA results indicated that ecological recovery was primarily influenced by surface temperature, vegetation cover, and soil moisture, with radioactive residues further hindering recovery in severely contaminated zones. The proportion of “Poor” areas declined from 14.99% to 0.61%, while “Moderate” and “Good” areas expanded to 55.76% and 8.87%, respectively. Peripheral regions showed faster recovery due to effective natural and management interventions, while core high-contamination zones (Sary-Uzen) exhibited slower recovery due to persistent radioactive residues. This study highlights the applicability of RSEI for assessing ecological recovery in nuclear test sites and emphasizes the need for targeted remediation strategies. These findings provide valuable insights for global ecological management of nuclear test sites, supporting sustainable restoration efforts. Full article

In recent years, high-entropy materials (HEMs) have emerged as a promising multifunctional material system, garnering significant interest in the field of photocatalysis due to their tunable microstructures, diverse compositions, and unique electronic properties. Owing to their multi-element synergistic effects and abundant active sites, high-entropy photocatalysts enable precise regulation over the separation efficiency of photo-generated charge carriers and surface reaction pathways, thereby significantly enhancing photocatalytic activity and selectivity. The high configurational entropy of these materials also imparts exceptional structural stability, allowing the catalysts to maintain long-term durability under harsh conditions, such as intense light irradiation, extreme pH levels, or redox environments. This provides a potential alternative to common issues faced by traditional photocatalysts, such as rapid deactivation and short lifespans. This review highlights recent advancements in the preparations and applications of HEMs in various photocatalytic processes, including the degradation of organic pollutants, hydrogen production, CO₂ reduction and methanation, H₂O₂ production, and N₂ fixation. The emergence of high-entropy photocatalysts has paved the way for new opportunities in environmental remediation and energy conversion. Full article

Remediating complex-contaminated soils demands the synergistic optimization of efficiency, cost-effectiveness, and carbon emission reduction. Currently, ultra-high-temperature thermal desorption technology is mature in terms of principle and laboratory-scale performance; however, ongoing efforts are focusing on achieving stable, efficient, controllable, and cost-optimized operation in large-scale engineering applications. To address this gap, this study aimed to (1) verify the energy efficiency and economic benefits of removing over 98% of target pollutants at a 7.5 × 10⁴ m³ contaminated site and (2) elucidate the mechanisms underlying parallel scale–technology dual-factor cost reduction and energy–carbon–cost optimization, thereby accumulating case experience and data support for large-scale engineering deployment. To achieve these objectives, a “thermal stability–chemical oxidizability” classification criterion was developed to guide a parallel remediation strategy, integrating ex situ ultra-high-temperature thermal desorption (1000 °C) with persulfate-based chemical oxidation. This strategy was implemented at a 7.5 × 10⁴ m³ large-scale site, delivering robust performance: the total petroleum hydrocarbon (TPH) and pentachlorophenol (PCP) removal efficiencies exceeded 99%, with a median removal rate of 98% for polycyclic aromatic hydrocarbons (PAHs). It also provided a critical operational example of a large-scale engineering application, demonstrating a daily treatment capacity of 987 m³, a unit remediation cost of 800 CNY·m⁻³, and energy consumption of 820 kWh·m⁻³, outperforming established benchmarks reported in the literature. A net reduction of 2.9 kilotonnes of CO₂ equivalent (kt CO₂e) in greenhouse gas emissions was achieved, which could be further enhanced with an additional 8.8 kt CO₂e by integrating a hybrid renewable energy system (70% photovoltaic–molten salt thermal storage + 30% green power). In summary, this study establishes a “high-temperature–parallel oxidation–low-carbon energy” framework for the rapid remediation of large-scale multi-contaminant sites, proposes a feasible pathway toward developing a soil carbon credit mechanism, and fills a critical gap between laboratory-scale success and large-scale engineering applications of ultra-high-temperature remediation technologies. Full article

Biochar is one of the most promising crop straw utilization pathways. However, its capacity for adsorbing heavy metals is limited, and there is a potential risk of secondary pollution, highlighting the importance of developing efficient and environmentally friendly bio-modification methods. Here, we utilized glomalin-related soil protein (GRSP), a byproduct from arbuscular mycorrhizal fungi, to modify straw biochar, developing a novel composite material and systematically evaluating its performance in removing copper ion (Cu²⁺) from aqueous solutions. Biochar samples derived from maize, wheat, and rice straw were prepared at three pyrolysis temperatures (300 °C, 500 °C, and 700 °C), followed by surface functionalization with GRSP to produce GRSP-modified straw biochar for Cu²⁺ adsorption experiments. The results demonstrated that the abundant functional groups (e.g., amino and carboxyl groups) in GRSP and the porous structure of the straw biochar exhibited a significant synergistic effect, enhancing the adsorption capacity for Cu²⁺. Notably, the GRSP-modified wheat straw biochar prepared at 700 °C achieved an adsorption capacity of 193.2 mg g⁻¹ for Cu²⁺, representing a 76% improvement over the unmodified material. Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy revealed that hydroxyl, carboxyl, and ether groups served as key adsorption sites for Cu²⁺, while the hydrophobic-acid precipitation characteristics of GRSP further enhanced the material’s recoverability. By systematically characterizing the material’s microstructure and its adsorption behavior toward Cu²⁺, this study elucidated the role of critical functional groups in the adsorption mechanism. This work not only offers a low-carbon and efficient strategy for agricultural waste valorization and heavy metal pollution control, but also advances the mechanistic understanding of “bio-abiotic” synergy in environmental remediation. Full article

The increasing contamination of neonicotinoid pesticides in the environment has become a growing concern, and biochar is considered a promising strategy for removing these pollutants. This study converted waste rice husks into biochar (RHB) via pyrolysis at 400–600 °C under anaerobic conditions, using dinotefuran (DIN) as a representative neonicotinoid. The physicochemical properties of RHB and its adsorption mechanisms for DIN were systematically investigated. Results showed that higher pyrolysis temperatures increased the specific surface area, microporosity, and aromaticity of biochar, while altering the distribution of surface functional groups. RHB prepared at 600 °C (RHB600) exhibited the highest adsorption capacity. The adsorption process followed the Sips isotherm and pseudo-second-order kinetic models, indicating a spontaneous and endothermic process involving heterogeneous physic–chemical adsorption. The primary mechanisms included pore filling, π–π interactions, and hydrogen bonding. The sequence of functional group response during DIN adsorption was C–O > C=C > C=O > –OH. Environmental factors such as solution pH and humic acid concentration significantly influenced adsorption, while phosphate ions caused strong competitive inhibition. An artificial neural network model accurately predicted adsorption under multiple interacting factors, and RHB600 demonstrated good regeneration after ethanol elution. This study confirms that RHB is an effective and practical adsorbent, providing a technical reference for agricultural waste valorization and pesticide-polluted water remediation. Full article

Presently, with rapid industrialization progressing, massive toxic pollutants have been discharged into nature, causing serious threats to ecosystems and human health. Thus, exploiting advanced functional materials for mitigating environmental challenges is vital. Among them, polyaniline (PANI)-based composites have gained great research attention because of their excellent mass–charge transfer ability, tunable morphology, rich N-containing functional groups, and high structural tunability. Herein, this review systematically summarizes the design principles, composite construction strategies, and adsorption applications of PANI-based composites. Key design principles, including micro-support skeleton construction, conductive skeleton introduction, and selective active site anchoring, are proposed. These principles aim to address defects of single components and realize the improvement of the properties, selectivity, and stability of PANI-based composites. Subsequently, multiple advanced PANI-based composites are further analyzed. Eventually, their applications in electrochemical (e.g., electrosorption) and non-electrochemical adsorption (e.g., typical adsorption) are comprehensively assessed. Overall, this review seeks to deliver valuable insights into the in-depth study of advanced PANI-based composites for effective pollutant remediation. Full article

Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with most vascular plants and play an important role in immobilizing heavy metals in soil. Urban green space ecosystems are increasingly affected by heavy metal pollution; however, how different types of green spaces influence AMF diversity, stability, and coexistence mechanisms under heavy metal stress remains unclear. Here, heavy metal-contaminated soil samples were collected from Zhengzhou, China—a large city in the warm temperate monsoon zone of the North China Plain—to conduct high-throughput sequencing and analyze AMF community assembly. (1) AMF community composition varied significantly among green space types, with higher diversity in park green spaces (Shannon = 21.24 ± 2.24) than in street green spaces (Shannon = 11.36 ± 1.17). (2) Heavy metals were the primary factors driving AMF community assembly. Stochastic processes, mainly dispersal limitation, dominated AMF assembly across sites, with a stronger influence in street green spaces. (3) Specialist taxa (mainly Glomus and Claroideoglomus) exhibited higher network connectivity and stability in park green spaces, whereas generalist taxa maintained network resilience in street green spaces. This study elucidates the ecological processes shaping AMF communities in urban ecosystems and provides a scientific basis for AMF-based approaches to heavy metal remediation and sustainable management of urban green spaces. Full article