Search Results (2,291)

Against the challenge of extreme lead (Pb) contamination (>15,000 ppm) in industrial polluted soils, where conventional agents fail to disrupt stable Pb–soil complexes—this study extends our prior cadmium (Cd) remediation research to validate amino acid ionic liquids (AAILs) for highly recalcitrant metals. Fifteen AAILs were screened via batch washing, with [Met][NO₃] (methionine-based) demonstrating the highest Pb removal efficiency. Single-factor optimization revealed that under the conditions of 0.8 mol/L, 6:1 liquid–soil ratio, 60 min, 85.4% Pb was removed from severely contaminated soil by [Met][NO₃]. Kinetic analysis using four common models showed that the second-order kinetic equation provided the best fit, indicating that Pb removal was predominantly driven by chemical reactions such as complexation or ion exchange. After washing, the contents of various Pb species were significantly reduced, thereby mitigating environmental risks. Notably, no substantial changes in soil texture were observed. However, a marked increase in organic matter content was detected, accompanied by decreases in soil pH and mineral element concentrations. Analysis of soil mineral composition, functional groups, and chemical speciation revealed that [Met][NO₃] primarily facilitated Pb removal through ion-exchange and coordination reactions. This study establishes [Met][NO₃] as a green agent with dual efficacy: it achieves high-efficiency remediation of severely Pb-contaminated soil while ensuring environmental sustainability, thus highlighting its potential for practical application. Full article

A high-performance Z-scheme heterojunction photocatalytic compound, ZnBiGdO₄/SnS₂ (ZS), was prepared for the first time using a microwave-assisted solvothermal method. ZS significantly improved the separation efficiency of photoinduced carriers and effectively broadened the response range to visible light through the unique mechanism of the Z-type heterojunction. Therefore, ZS exhibited an excellent photocatalytic performance during the degradation process of tinidazole (TNZ). Specifically, the removal rate of TNZ by ZS reached 99.63%, and the removal rate of total organic carbon (TOC) reached 98.37% with ZS as catalyst under visible light irradiation (VLIN). Compared to other photocatalysts, the photocatalytic performance of ZS was significantly better than that of ZnBiGdO₄, SnS₂, or N-doped TiO₂ (N-T). The removal rate of TNZ by ZS was 1.12 times, 1.26 times, or 2.41 times higher than that by ZnBiGdO₄, SnS₂, or N-T, respectively. The mineralization efficiency of TNZ for TOC with ZS as a catalyst was 1.15 times, 1.28 times, or 2.57 times higher than that with ZnBiGdO₄, SnS₂, or N-T as a catalyst, respectively. Free radical scavenging experiments and the electron paramagnetic resonance experiments confirmed that ZS could generate multiple reactive species such as hydroxyl radicals (•OH), superoxide anions (•O₂⁻), and photoinduced holes (h⁺) during the photocatalytic degradation process of TNZ. The photocatalytic degradation performance of ZS on TNZ under VLIN was evaluated, concurrently, the reliability, reproducibility, and stability of ZS were verified by five cycle experiments. This study explored the degradation mechanism and degradation pathway of TNZ with ZS as a catalyst under VLIN. This study not only provides new ideas for the design and preparation of Z-type heterojunction photocatalysts but also lays an important foundation for the development of efficient environmental remediation technologies for TNZ pollution. Full article

Organic and pharmaceutical pollution of water is a serious problem, particularly when it comes to drinking and groundwater. Although some evaluations indicate that these pollutants are unlikely to be at current exposure levels, they are often detected in aquatic systems and can be harmful to human health. Organic contaminants include hazardous micropollutants, aromatic phenols, pesticides, etc. Pharmaceutical contaminants are sulfamethoxazole, diclofenac, doxycycline, amoxicillin, trimethoprim, ciprofloxacin, norfloxacin, lipid regulators, nonsteroidal anti-inflammatory drugs (NSAIDs), hormones, antidepressants, etc. Hydrogel adsorbents’ distinct structural, chemical, and environmentally benign qualities make them a potential and successful option for environmental remediation, especially in wastewater treatment. In the search for clean water resources, they are an important instrument because of their reusability and capacity to be customized for certain contaminants, such as organic and pharmaceutical pollutants. This review focusses on the present state, adsorption sites and surfaces, different adsorption mechanisms, and the prospects and scope of improvement of effective hydrogels for eliminating dangerous aqueous organic and pharmaceutical contaminants. It offers a thorough summary of the area, highlighting its facets and potential paths forward. Full article

The production of alumina produces red mud (RM), a highly alkaline solid waste. The majority of it is disposed of in landfills, which seriously pollutes the environment. It needs to be recycled and handled with care to protect the environment. RM is a promising raw material for wastewater and waste gas treatment owing to its high alkalinity and abundant metal compounds. It can efficiently remove diverse pollutants while facilitating large-scale utilization of RM resources. Reviews of the use of RM resources to create catalysts for environmental governance are, nevertheless, scarce. Therefore, this paper analyzes and summarizes the pertinent research on RM-based catalysts to remove pollutants from the environment based on journal literature related to RM resource utilization from 2015 to 2025. This study reviews the application of RM-based catalysts for degrading pollutants in wastewater and exhaust gases via advanced oxidation processes (AOPs)—including photocatalysis, Fenton-like catalysis, ozonation catalysis, and persulfate catalysis—as well as catalytic oxidation, chemical looping combustion (CLC), and selective catalytic reduction (SCR). The paper emphasizes the analysis of modification strategies and catalytic mechanisms of RM-based catalysts in environmental remediation and examines the environmental risks and corresponding mitigation measures related to their preparation from RM resources. Finally, it outlines that future research should prioritize green, low-energy modification processes; catalytic systems for the synergistic removal of multiple pollutants; and efficient, recyclable separation and recovery technologies. These directions aim to promote the sustainable application of RM in large-scale environmental remediation and to achieve the integrated advancement of resource utilization and ecological protection. Full article

This study presents a general overview of the important problem of pharmaceutical pollutants, aiming to draw attention to the global danger they represent and the need for concrete solutions for their remediation. Here, we summarize the available advanced knowledge on the occurrence and fate of pharmaceutical residues in the environment, particularly in water effluents, since they need a special approach when one takes into account the increasing consumption of medicines by both humans and animals, that might be discharged in aqueous systems and bio-accumulated in aquatic flora and fauna. This review details the presence of pharmaceutical wastes in water sources; their trajectories from production to consumption and release in household taps; their concentrations in natural water; methods for monitoring them; their risks; and their worldwide impacts. Adequate methods and advanced removal techniques for selected contaminants or classes of pharmaceutical compounds are discussed, together with their remediation potential and strategies. Local and global limiting proposals for these types of contaminants and concrete solutions for their remediation are recommended. Full article

This study compared the effectiveness of the Sequencing Batch Biofilter Granular Reactor (SBBGR) plant with and without the integration of ozone (BIO-CHEM process) in the remediation of medium-aged landfill leachate. Special attention is given to the removal of per- and polyfluoroalkyl substances (PFAS) as a group of bioaccumulative and persistent pollutants. The findings highlight the high SBBGR performance under biological process only for key wastewater contaminants, with 82% for chemical oxygen demand (COD), 86% for total nitrogen, and 98% for ammonia. Moderate removal was observed for total (TSS) and volatile (VSS) suspended solids (41% and 44%, respectively), while phosphorus and colour removal remained limited. Remarkably, the SBBGR process achieved complete removal of long-chain PFAS, while its performance declined for shorter-chain PFAS. BIO-CHEM process significantly improved COD (87.7%), TSS (84.6%), VSS (86.7%), and colour (92–96%) removal. Conversely, ozonation led to an unexpected increase in the concentrations of several PFAS in the effluent, suggesting ozone-induced desorption from the biomass. SBBGR treatment was characterised by a low specific sludge production (SSP) value, i.e., 5–6 times less than that of conventional biological processes. SSP was further reduced during the application of the BIO-CHEM process. A key finding of this study is a critical challenge for PFAS removal in this combined treatment approach, different from other ozone-based methods. Full article

Soil–groundwater pollution is a complex environmental phenomenon formed by the coupling of multiple processes. Due to the concealment of pollution, the persistence of harm, and the complexity of the system, soil–groundwater pollution has become a major environmental issue of increasing concern. The simulation and prediction of different types of models, different pollutants, and different scales in soil and groundwater have always been the research hotspots for pollution prevention and control. Starting from the mathematical mechanism of pollutant transport in soil and groundwater, this study reviews the method models represented by empirical models, analytical models, statistical models, numerical models, and machine learning, and expounds the characteristics and applications of the various representative models. Our Web of Science analysis (2015–2025) identifies 3425 relevant studies on soil–groundwater pollution models. Statistical models dominated (n = 1155), followed by numerical models (n = 878) and machine learning (n = 703). Soil pollution studies (n = 1919) outnumber groundwater research (n = 1506), with statistical models being most prevalent for soil and equally common as numerical models for groundwater. Then this study summarizes the research status of soil–groundwater pollution simulation and prediction at the level of multi-scale numerical simulation and the pollutant transport mechanism. It also discusses the development trend of artificial intelligence innovation applications such as machine learning in soil–groundwater pollution, looks forward to the challenges and measures to cope with them, and proposes to systematically respond to core challenges in soil and groundwater pollution simulation and remediation through new technology development, multi-scale and multi-interface coupling, intelligent optimization algorithms, and pollution control collaborative optimization methods for pollution management, so as to provide references for the future simulation, prediction, and remediation of soil–groundwater pollution. Full article

This study examined the effect of sulfur, ethylenediaminetetraacetic acid (EDTA), olive mill wastewater (OMW), and their mixtures in remediating metal-polluted soils by implementing both leaching trials and a greenhouse experiment with sunflower (Helianthus annuus). In the leaching study, soils were subjected to five discharge volumes (V1–V5). EDTA significantly improved metal mobility of Cd (221.4) mg·kg⁻¹ in V2, Pb (340.8) mg·kg⁻¹ in V3, and Zn (1.01) mg·kg⁻¹ in V3, while OMW moderately mobilized Cd and Mn. However, sulfur mitigated leaching by buffering soil pH and metal immobilization. Mixed treatments revealed moderate leaching behavior. EDTA lowered soil pH (5.3) and raised EC (1763) µS/cm, while sulfur maintained stable chemical environments. In the greenhouse experiment, amendments significantly influenced biomass and metal uptake. Sunflower roots accumulated the highest Cd under sulfur (733.5) mg·kg⁻¹ and Mn under EDTA (743.3) mg·kg⁻¹. EDTA restricted Cd translocation (TF = 0), while OMW enhanced Cr movement to shoots (TF = 17.6). EDTA also reduced Cd bioavailability, whereas OMW raised Pb and Mn availability. Overall, EDTA improved metal solubility for potential removal and sulfur in stabilized metals, while OMW acted as a moderate mobilizer. Sunflower demonstrated selective metal uptake, indicating its potential in phytoremediation strategies tailored to specific contaminants. Full article

In response to the growing issue of iron and manganese pollution in water bodies, this study systematically investigated the adsorption performance of municipal sludge-derived biochar prepared at pyrolysis temperatures ranging from 300 to 700 °C for the removal of Fe²⁺ and Mn²⁺. Among the series of adsorbents (BC300–BC700), BC600—with its well-developed pore structure and high specific surface area—exhibited the best adsorption performance for both metal ions. Kinetic and isothermal adsorption experiments, in combination with XPS characterization, collectively revealed that (1) the adsorption mechanisms of Fe and Mn differ markedly, with Fe adsorption primarily governed by physical interactions, whereas Mn adsorption is largely controlled by chemical processes; (2) Fe²⁺ adsorption occurs mainly via electrostatic interactions and hydrogen bonding; and (3) Mn²⁺ forms carbonate precipitates with C=O groups during redox reactions. Thermodynamic analysis further indicated that the adsorption process was spontaneous and endothermic. Moreover, BC600 demonstrated excellent reusability for Fe adsorption across different water matrices, maintaining efficiencies above 95% after five cycles, although the adsorption performance for Mn declined. This study provides theoretical support for the application of sludge-derived biochar as a cost-effective and efficient adsorbent for metal ion remediation. Full article

Perfluorooctane sulfonate (PFOS) is a representative persistent organic pollutant that exerts toxic effects on aquatic organisms. As an alternative to PFOS, sodium p-perfluorous nonenoxybenzene sulfonate (OBS) has been frequently detected in aquatic environments and human tissues in recent years. However, its toxic effects on aquatic organisms and potential health risks to humans remain unclear. Zebrafish embryos are transparent and amenable to in vivo manipulation and observation. Therefore, in the present study, we investigated its developmental toxicity in zebrafish embryos, with PFOS as the positive control. We exposed zebrafish embryos to different concentrations of OBS (15, 20, and 25 mg/L) and PFOS (15 mg/L) for 2–168 h post fertilization (hpf) and then examined physiological and gene expression changes. At 24 hpf, spontaneous twitches in the 25 mg/L OBS group decreased to (5 ± 0.34)/min. By 48 hpf, the 20 mg/L OBS group’s hatching rate was (47.78 ± 2.22)%, significantly lower than the control. At 72 hpf, heart rates in both the PFOS and OBS groups were elevated, at 82 ± 0.6, 84.5 ± 0.5, 89.4 ± 0.3, and 93.7 ± 0.4, respectively. Similarly to PFOS, OBS induced developmental toxicity in zebrafish embryos. In addition, both OBS and PFOS exposure downregulated the expression level of anti-apoptotic Bcl-2 in zebrafish embryos, with a notable 0.53-fold decrease observed in the 25 mg/L OBS group. Conversely, they upregulated the expression levels of pro-apoptotic Bax, Caspase-3, and Caspase-9, with Caspase-3 expression increasing 1.14-, 1.5-, and 1.7-fold in the 15 mg/L PFOS, 20 mg/L OBS, and 25 mg/L OBS groups, respectively. These OBS- and PFOS-induced changes in gene expression increased apoptosis, suggesting that OBS can induce developmental toxicity in zebrafish embryos, and that its effect is comparable to that of PFOS. Therefore, considering its aquatic toxicity, measures aimed at limiting or remediating OBS pollution in the environment are necessary. Full article

Industrial pollution caused by Cu(II) ions remains one of the most critical environmental challenges worldwide. A novel green-fluorescent aerogel has been successfully developed for simultaneous sensing and adsorption of Cu(II) through the cross-linking of carboxymethyl nanocellulose and carbon dots (C dots) using epichlorohydrin as a linker. The C dots were synthesized by heating glucose and aspartate mixed solutions at 150 °C. Under UV illumination, the aerogel exhibited intense homogeneous green fluorescence originating from the uniformly dispersed C dots, whose emission can be efficiently quenched by Cu(II) ions. By leveraging smartphone-based imaging, the concentration of Cu(II) was quantified within the range of 5–200 µg/L, with a detection limit of 3.7 µg/L. The adsorption isotherm of Cu(II) onto the aerogel strictly conformed to the Freundlich isotherm model (fitting coefficient R² = 0.9992), indicating a hybrid adsorption mechanism involving both physical adsorption and chemical complexation. The maximum adsorption capacity reached 149.62 mg/g, a value surpassing many reported adsorbents. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy analyses confirmed that the interactions between the aerogel and Cu(II) involved chelation and redox reactions, mediated by functional groups such as hydroxyl, amino, and carboxyl moieties. The straightforward fabrication process of the aerogel, coupled with its low cost, abundant raw materials, facile synthesis, and superior Cu(II) removal efficiency, positions this bifunctional fluorescent material as a promising candidate for large-scale environmental remediation applications. Full article

This study was conducted in nine allotment garden complexes in Wrocław, West Poland (Central Europe). Soil samples were collected from each garden and analyzed for their total concentrations of Zn, Cu, Pb and Cd, alongside the percentage of organic carbon C. Contaminant levels varied widely between sites: Zn ranged from 101.1 to 3464.5 mg/kg, Cu from 24.93 to 322.45 mg/kg, Cd from 0.51 to 6.31 mg/kg, and Pb from 19.92 to 401.85 mg/kg. The highest metal contamination was found for the garden complex placed on the former impact of the Hutmen. The organic carbon content ranged from 2.12% to 7.64%, indicating substantial variability in organic matter levels across the studied sites. This variability may significantly influence the soils’ capacity to retain heavy metals. A significant positive correlation was observed between soil organic carbon and the total concentrations of Pb, Cu and Zn, suggesting that soils richer in organic matter may retain higher levels of heavy metals. These findings underscore the dual role of organic matter as both a beneficial soil component and a potential contributor to heavy metal retention in urban garden soils. Protecting and enhancing SOM in polluted soils is a beneficial strategy, remediating environmental damage while aligning with global sustainability goals. Full article

Intensified human activities in recent years, such as wastewater discharge and agricultural non-point source pollution have led to a decline in lake water quality, especially in the middle and lower reaches of the Yangtze River Basin, which threaten the stability of lake water ecosystems. Therefore, it is necessary to conduct a scientific assessment of the water eco-environmental quality of shallow lakes and implement targeted management measures. Considering the characteristics of shallow lakes, major ecological and environmental issues, and current standards and guidelines, an indicator system method was employed to establish a water eco-environmental quality evaluation system tailored for typical shallow lakes in the middle and lower reaches of the Yangtze River Basin. This evaluation system comprises three criteria layers (aquatic organism, habitat quality, and water quality) and 10 indicator layers. Using survey data from 2022 to 2024 for evaluation, the results showed that the water eco-environmental quality of Lake Gehu was rated as poor, with the lowest score for macrophyte coverage and the highest score for riparian vegetation coverage. This indicates that the shoreline restoration project in Lake Gehu was effective, while the lake water quality still needs improvement. Remedial measures include increasing aquatic vegetation coverage, reducing nitrogen and phosphorus pollution loads, and controlling the occurrence of algal blooms. This evaluation system combines field surveys with remote sensing monitoring data, fully considering historical and current conditions, and can guide local authorities in evaluating lake water environmental quality. The constructed evaluation system is applicable for the assessment of shallow lakes in the middle and lower reaches of Yangtze River Basin. It provides a scientific basis for the continuous improvement of eco-environmental quality and the construction of Beautiful Lakes Initiative, contributing to the management and protection of lake ecosystems. Full article

This study explores the adsorption and catalytic degradation of 2,4,6-trinitrotoluene (TNT) from aqueous solutions, using montmorillonite-based catalysts. Commercially, montmorillonite K10 was modified through aluminum pillaring (K10-Al-PILC), followed by vanadium intercalation (K10-Al-PILC-V) and ozone activation. A novel aspect of this work is the use of naturally contaminated water as the TNT source. The selected sample, collected from the Plaiul Arșiței–Cireșu–Leșunț region (Oituz, Bacau, Romania), originated from an area historically exposed to explosive residues, where TNT traces were previously identified. The adsorption performance of the materials was evaluated by varying adsorbent dosage, contact time, and solution pH. Catalytic ozonation experiments were conducted under different catalyst masses, ozone concentrations, and reaction times to assess degradation efficiency. The results demonstrated that aluminum pillaring significantly enhanced the adsorption capacity of the clay, while vanadium incorporation further improved both adsorption and catalytic activity. The vanadium-modified material exhibited superior performance in TNT removal, both through adsorption and oxidative degradation. Additionally, the catalytic ozonation process led to the formation of degradation products with reduced toxicity, confirming the potential of these materials for environmental remediation of nitroaromatic pollutants in real water systems. Full article

Heavy metals represent long-lasting contaminants that pose significant risks to both human health and ecosystem integrity. Originating from both natural and anthropogenic activities, they bioaccumulate in organisms through the food web, leading to widespread and long-lasting contamination. Industrialization, agriculture, and urbanization have exacerbated soil and water contamination through activities such as mining, industrial production, and wastewater use. In response to this challenge, biochar produced from waste materials such as sewage sludge has emerged as a promising remediation strategy, offering a cost-effective and sustainable means to immobilize heavy metals and reduce their bioavailability in contaminated environments. Here we explore the potential of phosphate-enriched biochar, derived from sewage sludge, to adsorb and stabilize heavy metals in polluted soils. Sewage sludge was pyrolyzed at various temperatures to produce biochar. A soil incubation experiment was conducted by adding phosphate-amended biochar to contaminated soil and maintaining it for one month. Heavy metals were extracted using a CaCl₂ extraction method and analyzed using atomic absorption spectrophotometry. Results demonstrated that phosphate amendment significantly enhanced the biochar’s capacity to immobilize heavy metals. Amending soils with 2.5 wt% phosphate-enriched sewage sludge biochar led to reductions in bioavailable Cd (by 65–82%), Zn (40–75%), and Pb (52–88%) across varying pyrolysis temperatures. Specifically, phosphate-amended biochar reduced the mobility of Cd and Zn more effectively than unamended biochar, with a significant decrease in their concentrations in soil extracts. For Cu and Pb, the effectiveness varied with pyrolysis temperature and phosphate amendment, highlighting the importance of optimization for specific metal contaminants. Biochar generated from elevated pyrolysis temperatures (500 °C) showed an increase in ash content and pH, which improved their ability to retain heavy metals and limit their mobility. These findings suggest that phosphate-amended biochar reduces heavy metal bioavailability, minimizing their entry into the food chain. This supports a sustainable approach for managing hazardous waste and remediating contaminated soils, safeguarding ecosystem health, and mitigating public health risks. Full article