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Polluted environments often contain large amounts of toxic metals, such as cadmium, which pose a major threat to ecosystems and public health. Contamination by cadmium and its compounds is often observed in areas surrounding zinc mining sites and electroplating factories, and the control of cadmium pollution is essential for environmental safety and health. In this study, a highly efficient and straightforward separation strategy for K4Fe(CN)6@Fe3O4 nanocomposites is successfully developed to capture the Cd ions in the water environment. Batch adsorption experiments revealed that K4Fe(CN)6@Fe3O4 exhibited a high cadmium removal rate (greater than 98â¯%) at a pH level of 6.0 and solid-liquid ratio of 1.0â¯g/L at room temperature (298â¯K). Kinetic analysis revealed that the adsorption process followed a pseudo-second-order model and cadmium was rapidly removed in the first 10â¯min, with chemisorption dominating the capture of Cd2+ by K4Fe(CN)6@Fe3O4. Adsorption isotherms revealed a heterogeneous adsorption behavior, with a maximum adsorption capacity of 40.78â¯mg/g. The intrinsic adsorption of Cd2+ by K4Fe(CN)6@Fe3O4 occurring primarily through electrostatic interaction and ion exchange. In addition, K4Fe(CN)6@Fe3O4 exhibited an excellent regeneration capacity. Therefore, integrating Fe3O4 into the metal cyanide not only provided the composite material with excellent chemical stability and selective adsorption sites for Cd2+, but also facilitated subsequent sorbent collection and recovery. Overall, this study presents a simple and feasible approach for integrating Fe3O4 into potassium ferrocyanide frameworks for efficient cadmium removal from contaminated water.
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Cadmio , Ferrocianuros , Contaminantes Químicos del Agua , Cadmio/química , Cadmio/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Adsorción , Ferrocianuros/química , Cinética , Purificación del Agua/métodos , Concentración de Iones de Hidrógeno , Nanocompuestos/químicaRESUMEN
Spliceosome machinery mutations are common early mutations in myeloid malignancies; however, effective targeted therapies against them are still lacking. In the current study, we used an in vitro high-throughput drug screen among four different isogenic cell lines and identified RKI-1447, a Rho-associated protein kinase inhibitor, as selective cytotoxic effector of SRSF2 mutant cells. RKI-1447 targeted SRSF2 mutated primary human samples in xenografts models. RKI-1447 induced mitotic catastrophe and induced major reorganization of the microtubule system and severe nuclear deformation. Transmission electron microscopy and 3D light microscopy revealed that SRSF2 mutations induce deep nuclear indentation and segmentation that are apparently driven by microtubule-rich cytoplasmic intrusions, which are exacerbated by RKI-1447. The severe nuclear deformation in RKI-1447-treated SRSF2 mutant cells prevents cells from completing mitosis. These findings shed new light on the interplay between microtubules and the nucleus and offers new ways for targeting pre-leukemic SRSF2 mutant cells.
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Uranium contamination and remediation is a very important environmental research area. Removing radioactive and toxic uranium from contaminated media requires fundamental knowledge of targets and materials. To explore the-State-of-the-Art in uranium contamination control, we employed a statistical tool called CiteSpace to visualize and statistically analyze 4203 peer-reviewed papers on uranium treatment published between 2008 and 2022. The primary content presentations of visual analysis were co-authorships, co-citations, keyword co-occurrence analysis with cluster analysis, which could offer purposeful information of research hots and trends in the field of uranium removal. The statistical analysis results indicated that studies on uranium removal have focused on adsorption of uranium from aqueous solution. From 2008 to 2022, biochar and biological treatment were firstly used to sequester uranium, then adsorption for uranium removal dominates with adsorbents of graphene oxide, primary nanofiber magnetic polymers and metal-organic frameworks (MOFs). In recent years, photocatalysts and metal-organic frameworks are expected to be two of the most popular research topics. In addition, we further highlighted the characteristics and applications of MOFs and GOs in uranium removal. Overall, a statistical review was proposed to visualize and summarize the knowledge and research trends regarding uranium treatment.
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Estructuras Metalorgánicas , Uranio , Adsorción , Análisis por Conglomerados , CalorRESUMEN
Speciation of thallium (Tl) controls its fate and biogeochemical behaviors. Thus, a sensitive and accurately approach for Tl monitoring is of great demand due to its ultra-low concentration and sensitivity to redox change. In this study, diffusive gradients in thin-films technique (DGT) assembled with novel titanium peroxide (TP) binding gels (TP-DGT) was developed for in situ measurement of dissolved Tl(I) and Tl(III) in waters and sediments. Laboratory test showed a linear mass accumulation of Tl(I) and Tl(III) on the TP binding gels with the deployment time from 4 to 72 h. A fascinating performance of this novel DGT was achieved in a pH range of 4-9, ionic strength range of 0.1-200 mmol L-1, and humic acid concentration of 0-30 mg L-1 with a low detection limit of 0.3 ng L-1 for Tl(I) and 0.6 ng L-1 for Tl(III). The TP binding gels own excellent stability (1-365 d) and high capacity (73.5 µg Tl disc-1) which are suitable for long-term monitoring. Field application in a river indicated that TP-DGT could work effectively, comparable to the grab sampling in waters. For the first time, the TP-DGT coupled with oxygen optode was successfully applied to map 2D distribution patterns of Tl and oxygen simultaneously in the rhizosphere of M. verticillatum L. This study confirms TP-DGT is a promising tool for routine monitoring of Tl in waters and for investigating biogeochemical processes of Tl in sediments.
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Uranium-containing wastewater is a common by-product of uranium mining. Phosphate and phosphate minerals can interact with uranyl ions [U(VI)], impeding the migration of these ions by forming relatively stable uranium-containing crystalline phase(s). In this study, hydroxyapatite microtubes (HAP-T) were fabricated to sequester uranyl ions from simulated radioactive wastewater. HAP-T had excellent adsorption and stability properties; over 98.76% of U(VI) could be sequestrated by 0.25 g/L HAP-T within 5 min at pH = 4.0. The isotherms and kinetics data could be suitably reflected by the Freundlich and the pseudo second-order kinetic models, respectively. The maximum adsorption capacity of HAP-T was 356.42 mg/g. The adsorption ability of HAP-T for U(VI) was inhibited when Mg2+ or SO42- ions or fulvic acid (FA) substances existed in the simulated radioactive wastewater. The inhibition by FA was attributed to its negative charges, which caused competition between FA and HAP-T for uranium sequestration. The primary mechanisms of U(VI) sequestration by HAP-T were electrostatic interactions and surface complexation. The effectiveness of HAP-T, HAP-B (bio-hydroxyapatite synthesized from fish bone), and HAP-C (commercially available synthesized hydroxyapatite) for uranium immobilization was compared; HAP-T was more effective than HAP-B or HAP-C in immobilizing uranium. HAP-T, which has a micron-sized tubular structure, is likely less mobile in groundwater than are HAP-B and HAP-C, which have nanoscale granular structures. In conclusion, HAP-T can be used to sequester and immobilize uranyl ions.
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Durapatita , Uranio , Durapatita/química , Uranio/análisis , Aguas Residuales , Adsorción , CinéticaRESUMEN
Heavy metal pollution has resulted in serious environmental damage and raised significant public health concerns. One potential solution in terminal waste treatment is to structurally incorporate and immobilize heavy metals in some robust frameworks. Yet extant research offers a limited perspective on how metal incorporation behavior and stabilization mechanisms can effectively manage heavy metal-laden waste. This review sets forth detailed research on the feasibility of treatment strategies to incorporate heavy metals into structural frameworks; this paper also compares common methods and advanced characterization techniques for identifying metal stabilization mechanisms. Furthermore, this review analyses the typical hosting structures for heavy metal contaminants and metal incorporation behavior, highlighting the importance of structural features on metal speciation and immobilization efficiency. Lastly, this paper systematically summarizes key factors (i.e., intrinsic properties and external conditions) affecting metal incorporation behavior. Drawing on these impactful findings, the paper discusses future directions in the design of waste forms that efficiently, effectively treat heavy metal contaminants. By examining tailored composition-structure-property relationships in metal immobilization strategies, this review reveals possible solutions for crucial challenges in waste treatment and enhances the development of structural incorporation strategies for heavy metal immobilization in environmental applications.
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The widespread adoption of nuclear energy has increased the amount of radioactive cesium (Cs) that is discharged into waste streams, which can have environmental risks. In this paper, we provide a comprehensive summary of current advances in aqueous Cs removal by employing a bibliometric analysis. We collected 1580 articles related to aqueous Cs treatment that were published on the Web of Science database between 2012 and 2022. By applying bibliometric analysis combined with network analysis, we revealed the research distribution, knowledge base, research hotspots, and cutting-edge technologies in the field of aqueous Cs removal. Our findings indicate that China, Japan, and South Korea are the most productive countries with respect to Cs removal research. In addition, both historic events and environmental threats might have contributed to research in Asian countries having a higher focus on Cs removal as well as strong international cooperation between Asian countries. A detailed keyword analysis reveals the main knowledge base for aqueous Cs removal and highlights the potential of the adsorption-based method for treating Cs contamination. Furthermore, the results reveal that exploration of functional materials is a popular research topic in the field of Cs removal. Since 2012, novel materials, including Prussian blue, graphene oxide, hydrogel and nanocomposites, have been widely investigated because of their high capacity for Cs removal. On the basis of the detailed information, we report the latest research trends on aqueous Cs removal, and propose future research directions and describe the challenges related to effective Cs treatment. This scientometric review provides insights into current research hotspots and cutting-edge trends in addition to contributing to the development of this crucial research field.
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Cesium (Cs) is a byproduct of nuclear bombs, nuclear weapons testing, and nuclear fission in nuclear reactors. Cs can enter the human body through food or air and cause lasting damage. Highly efficient and selective removal of 137Cs from low-level radioactive effluents (LLREs), which contain many radionuclides and dissolved heavy metal species, is imperative for minimizing LLRE volume, and facilitating their final disposal. Prussian blue analogs (PBAs) have received much attention as materials for the removal of radioactive Cs because of their affinity for adsorbing Cs+. In this study, an inexpensive and readily available cyanide-based functional material (PBACu) exhibiting high efficiency and excellent selectivity toward Cs capture was designed through a facile low-temperature co-precipitation process. Nano-PBACu, crystallizing in the cubic space group (Fm-3m (225)), has an average pore size of 6.53 nm; consequently, PBACu can offer abundant atomic occupation sites for capturing and incorporating Cs. Here, the pseudo-second-order kinetic model and Langmuir model fitted well with the adsorption of Cs + on PBACu, with a maximum capture capacity of 95.75 mg/g within 5 min, confirming that PBACu could rapidly capture Cs ions. PBACu strongly and selectively interacted with Cs even in a simulant containing large Na+, NH4+, Ca2+, and Mg2+ ion concentrations in an aqueous solution. The process of Cs + adsorption by cyanide-based functional crystals was confirmed to involve the entry of Cs+ into cyanide-based functional crystals to replace K+ and finally achieve the lattice incorporation of Cs. The current results broaden the lattice theory of radionuclide Cs removal and provide a promising alternative for the immobilization of Cs from radioactive wastewater.
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Cesio , Cianuros , Adsorción , Cesio/química , Humanos , Concentración de Iones de Hidrógeno , Aguas Residuales/químicaRESUMEN
Cathode electrocatalyst is quite critical to realize the application of microbial fuel cells (MFCs). Perovskite oxides have been considered as potential MFCs cathode catalysts to replace Pt/C. Herein, Cu-doped perovskite oxide with a stable porous structure and excellent conductivity was successfully prepared through a sol-gel method. Due to the incorporation of Cu, CaFe0.9Cu0.1O3 has more micropores and a larger surface area, which are more conducive to contact with oxygen. Doping Cu resulted in more Fe3+ in B-site and thus enhanced its binding capability to oxygen molecules. The data from electrochemical test demonstrated that the as-prepared catalyst has good conductivity, high stability, and excellent ORR properties. Compared with Pt/C catalyst, CaFe0.9Cu0.1O3 exhibits a lower overpotential, which had an onset potential of 0.195 V and a half-wave potential of -0.224 V, respectively. CaFe0.9Cu0.1O3 displays an outstanding four-electron pathway for ORR mechanism and demonstrates superiors corrosion resistance and stability. The MFC with CaFe0.9Cu0.1O3 has a greater maximum power density (1090 mW m-3) rather than that of Pt/C cathode (970 mW m-3). This work demonstrated CaFe0.9Cu0.1O3 is an economic and efficient cathodic catalyst for MFCs.
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Fuentes de Energía Bioeléctrica , Compuestos de Calcio , Catálisis , Electrodos , Óxidos/química , Oxígeno/química , TitanioRESUMEN
Recent studies highlighted the role of transcription factors in metabolic regulation during hematopoiesis and leukemia development. GFI1B is a transcriptional repressor that plays a critical role in hematopoiesis, and its expression is negatively related to the prognosis of acute myeloid leukemia (AML) patients. We earlier reported a change in the metabolic state of hematopoietic stem cells upon Gfi1b deletion. Here we explored the role of Gfi1b in metabolism reprogramming during hematopoiesis and leukemogenesis. We demonstrated that Gfi1b deletion remarkably activated mitochondrial respiration and altered energy metabolism dependence toward oxidative phosphorylation (OXPHOS). Mitochondrial substrate dependency was shifted from glucose to fatty acids upon Gfi1b deletion via upregulating fatty acid oxidation (FAO). On a molecular level, Gfi1b epigenetically regulated multiple FAO-related genes. Moreover, we observed that metabolic phenotypes evolved as cells progressed from preleukemia to leukemia, and the correlation between Gfi1b expression level and metabolic phenotype was affected by genetic variations in AML cells. FAO or OXPHOS inhibition significantly impeded leukemia progression of Gfi1b-KO MLL/AF9 cells. Finally, we showed that Gfi1b-deficient AML cells were more sensitive to metformin as well as drugs implicated in OXPHOS and FAO inhibition, opening new potential therapeutic strategies.
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Hematopoyesis , Leucemia Mieloide Aguda , Proteínas Proto-Oncogénicas , Proteínas Represoras , Hematopoyesis/genética , Hematopoyesis/fisiología , Células Madre Hematopoyéticas , Humanos , Leucemia Mieloide Aguda/metabolismo , Síndromes Mielodisplásicos , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Represoras/metabolismo , Factores de TranscripciónRESUMEN
As a type of useful solid waste, red mud (RM) should be reused to achieve waste-to-resource strategies. Additionally, the fast development of nuclear industry requires effective and reliable materials for treating uranium (U)-containing wastewater. This study attempted to remove uranyl ions [U(VI)] from mimic radioactive wastewater by various RM particles with different size fractions (e.g., >75, 45-75, 20-45, 10-20, 5-10, and <5-µm). Sorption data confirmed that the RM with a size fraction of <5-µm exhibited the largest adsorption capacity. The U removal behavior was favorably described by the pseudo-second-order model and Langmuir model. The mineral phases in the RM remarkably influenced U(VI) removal. Cancrinite, katoite, grossular, calcite, and calcium aluminum silicate phases made contributions to U(VI) adsorption. In addition, redox precipitation with iron-bearing minerals on RM surface also led to U(VI) adsorption. The findings of this work offer fundamental knowledge on the potential application of RM for clean-up of U(VI) from contaminated sites.
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Uranio , Contaminantes Radiactivos del Agua , Adsorción , Carbonato de Calcio , Concentración de Iones de Hidrógeno , Uranio/análisis , Aguas Residuales , Contaminantes Radiactivos del Agua/análisisRESUMEN
Previous studies demonstrate that the leaching of heavy metals in unreliable waste forms causes serious environmental pollution and health concerns. Thus, research is focused on identifying an effective, safe strategy for disposing of metal-laden solid waste such as lead (Pb). This study evaluated the effect of anion replacement in the structure of pyromorphite (Pb10(PO4)6Cl2, a common mineral phase for Pb sequestering) on Pb stabilization. Phosphate (PO43-) at the tetrahedral pyromorphite site was simultaneously replaced by silicate (SiO44-) and sulphate (SO42-) in a controlled thermal treatment. The lattice expanded with the incorporation of additional SiO44- and SO42-. Furthermore, the unit cell parameters of the solid solutions evolved linearly with an increase in the substitution degree (x in Pb10(SiO4)x(SO4)x(PO4)(6-2x)Cl2). This research also demonstrated that Pb distributed into amorphous in a PO43--deficient matrix, while asisite (Pb7SiO8Cl2) was formed when the matrix was dominated by SiO44- and SO42-. The leaching results showed the isomorphous substitution in the target system rendered the products less durable towards acidic attack. Moreover, the fully isomorphous-substituted product (x = 3) showed more than two orders of magnitude lower leaching resistance than the PO43--rich phase (x = 0). The lattice expansion, resulting from the isomorphous substitution, suggested that a lower dissolution energy was required in a PO43--deficient matrix. The leaching kinetics pointed to a product with a lower apparent activation energy in the leaching process. The findings of this study provide unique insight into the design and optimization of waste forms for the immobilization of heavy metals.
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Plomo , Metales Pesados , Metales Pesados/química , Minerales/química , Fosfatos/químicaRESUMEN
The migration and transformation of uranyl [U (â ¥)] ions in the environment are quite dependent on the geological condition in particular with the site enriched in Fe. In this study, the interfacial interaction of U (â ¥) ions with maghemite (γ-Fe2O3) particles was studied and the interaction mechanism was explored as well. Batch experiments confirm that γ-Fe2O3 can effectively remove U (â ¥) from an aqueous solution within a relatively short reaction time (R% > 92.01% within 3 min) and has a considerable capacity for U (â ¥) uptake (qt: 87.35 mg/g). γ-Fe2O3 displays an excellent selectivity for U (â ¥) elimination. Results on the effects of natural organic matter such as humic acid (HA) indicated that HA could promote the interfacial interaction between γ-Fe2O3 and U (â ¥) under acidic conditions. Compared with other radionuclides (e.g., Sr(â ¡) and Cs(â )), U (â ¥) was more effectively removed by γ-Fe2O3. The U (â ¥) removal by γ-Fe2O3 is primarily due to electrostatic interactions and precipitation that result in the long-term retardation of uranium. γ-Fe2O3 not only can fast and selectively adsorb U (â ¥) but also can be magnetically recycled, demonstrating that γ-Fe2O3 is a cost-effective and promising material for the clean-up of uranyl ions from radioactive wastewater.
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Uranio , Contaminantes Químicos del Agua , Adsorción , Sustancias Húmicas/análisis , Aguas ResidualesRESUMEN
Heterocyclic aromatic compounds such as malachite green can cause immense harm to the environment and mankind because of their toxic bio-accumulation and insufficient biodegradation. ZnFe2O4/TiO2 (ZF-T) has attracted attentions as a visible-light-driven catalyst because it can break and mineralize benzene through photolysis. Compared with TiO2, which photodegrades only 53.5% malachite green, anatase TiO2 loaded with ZnFe2O4 has greater photocatalytic activity and can degrade up to 90.1% malachite green. Furthermore, a photocatalytic efficiency above 80% can be obtained through five consecutive cycles with a duration of 4 h. In this study, ZF-T was characterized, and its photolytic parameters, including dosage, pH, time, and ionic strength, were optimized. The photolytic products of malachite green were analyzed by ultraviolet-visible spectroscopy and liquid chromatography-mass spectrometry, which confirmed that ZF-T can drive visible light to produce â¢O2- and H+ free radicals that can efficiently degrade heterocyclic aromatic hydrocarbons and cleave benzene rings. These outcomes deepen our understanding of the development and applications of visible-light-driven ZF-T composites in the field of wastewater purification.
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Benceno , Titanio , Catálisis , Luz , Colorantes de Rosanilina , Titanio/químicaRESUMEN
Uranium (U) immobilization from wastewater by zero valent iron (ZVI) was widely concerned through reduction and surface adsorption. Releasing of U due to re-oxidation of U(IV) into U(VI) limited the application of ZVI in U decontamination. In this work, a kind of biochar supported nano zero valent iron (Fe/BC(900)) was obtained by carbothermal reduction of starch mixed with ferric nitrate at 900 °C. U immobilization behavior by Fe/BC(900) in the presence of phosphate (P) was investigated. The U immobilization reaction was adjusted by controlling the sequence of U, Fe/BC(900) and P. U immobilization efficiency was enhanced to 99.9% in the presence of P. Reaction sequence of U, Fe/BC(900) and P influenced the U immobilization efficiency, which followed the order of (U-P)+Fe/BC(900)>(U- Fe/BC(900))+P>U+Fe/BC(900)>(P-Fe/BC(900))+U. P and nZVI both contributed to enhancing U immobilization through precipitation of uranyl-P and reductive co-precipitate (U(IV)) in a wide pH range. The released Fe ions could precipitate with uranyl and phosphate. Consumption of P and nZVI in the (P-Fe/BC(900))+U system limited U immobilization ability. The precipitate is highly dependent on U, P and Fe elements. U desorption in (U-P)+Fe/BC(900) system was not observed with stability.
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Uranio , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Hierro/análisis , Fosfatos , Contaminantes Químicos del Agua/análisisRESUMEN
Halloysite nanotubes (HNTs) are considered structurally promising adsorption materials, but their application is limited due to their poor native adsorption properties. Improving the adsorption capacity of HNTs for radioactive U(VI) is of great significance. By controlling the mass ratio of HNTs and dopamine (DA), composite adsorbents (HNTs@PDA) with different polydopamine (PDA) layer thicknesses were synthesized. Characterization of HNTs@PDA demonstrated that the original structure of the HNTs was maintained. Adsorption experiments verified that the adsorption capacity of HNTs@PDA for U(VI) was significantly improved. The effects of solution pH, temperature, and coexisting ions on the adsorption process were investigated. The removal efficiency was observed to be 75% after five repeated uses. The adsorption mechanism of U(VI) by HNTs@PDA can be explained by considering electrostatic interactions and the complexation of C-O, -NH- and C-N/CN in the PDA layer. This study provides some basic information for the application of HNTs for U(VI) removal.
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Nanotubos , Uranio , Arcilla , Indoles , PolímerosRESUMEN
Mining activities frequently result in severe contamination of river water. This study aimed to better understand the spatial distribution characteristics of Tl and other metals (e.g., Al, Cd, Co, Mn, Ni, Zn, Pb, V, As, Mo, and Sb), and to assess their risks to human health. Surface water samples were collected from the upper Beijiang River (South China) via grab sampling and the diffusive gradients in thin-films (DGT) technique. The concentrations of Tl measured by grab sampling and δ-MnO2-DGT ranged from 0.045 µg L-1 to 0.231 µg L-1 and from 0.056 µg L-1 to 0.131 µg L-1, respectively. Most of the metals monitored were below the threshold levels allowed by the drinking water standard in China, except for As, Sb, and Mn at specific sampling sites. The concentrations of other metals measured by grab sampling were higher than those measured using the DGT technique because of the differences in speciation during these measurements. The hazard quotient (5.43 × 10-4-8.0 × 10-1 for grab sampling and 2.23 × 10-4-2.8 × 10-1 for DGT technique) for the monitored trace metals demonstrated minimal health risk to human beings. The pollution status of these toxic metals in the study area was generally acceptable. As was found to be potentially the most harmful metal in the studied area, with hazard quotients at some sampling sites calculated by grab sampling of >1. It has previously been suggested that As is the most important non-carcinogenic contaminant. The combination of grab sampling and the DGT technique provides a comprehensive understanding of trace metals, especially Tl, in terms of potential bioavailability and ecological assessment.
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Ríos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Humanos , Compuestos de Manganeso , Óxidos , Talio , Contaminantes Químicos del Agua/análisisRESUMEN
Nano zero-valent iron (nZVI) is widely used for decontamination. The main issues associated with nZVI are agglomeration and oxidation in the long term. In this study, the carbothermal reduction of cotton fiber was conducted for the synthesis of nZVI supported on cotton carbon fiber (nZVI/CF) to address the agglomeration and oxidation of nZVI. Synergistic adsorption and peroxymonosulfate (PMS) activation using nZVI/CF for removing levofloxacin (LEV) are reported herein. The nZVI concentration and morphology were conveniently adjusted by soaking cotton fiber in ferric nitrate solutions of various Fe3+ concentrations. The carbothermal reduction of the cotton fiber at 900 °C contributed to the reduction of Fe3+ into nZVI. A nZVI/CF-900-0.3 system was obtained through the carbothermal reduction of cotton fiber soaked in 0.3 M ferric nitrate. Favorable adsorption of nZVI/CF-900-0.3 to LEV facilitated LEV degradation under PMS activation. Approximately 93.83% of LEV (C0 = 20 ppm) was removed within 60 min with 0.2 g/L of the catalyst and 1 mM PMS. It was preferable to use nZVI + CF-900 to activate PMS for degrading LEV, thus confirming the favorable effect of LEV adsorption on further degradation. The nZVI/CF-900-0.3 exhibited excellent long-term stability given that it was able to activate PMS after it was stored for 6 months. ·SO4- played an important role in LEV degradation in the presence of PMS.
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Hierro , Contaminantes Químicos del Agua , Adsorción , Fibra de Carbono , Levofloxacino , Peróxidos , Contaminantes Químicos del Agua/análisisRESUMEN
Fly ash from municipal solid waste incineration (MSWI) enriches many leachable toxic metals which readily migrate into the environment, posing serious risks to the ecosystem and human. In this study, the elements mobility, leaching availability as well as the potential maximum amounts of heavy metals in fly ash were thoroughly evaluated. To decontaminate the toxic elements from resulting fly ash leachates, The aqueous zinc (Zn) was recovered using Cyanex 572, cadmium (Cd) and copper (Cu) were effectively removed through adsorption process by a self-assembled hierarchical hydroxyapatite (HAP) nanostructure. The removal mechanism of Cd, Cu and Zn by leaching, extraction and adsorption was revealed with the results from XRD, ICP-MS and SEM. The results showed that fly ash has a high mobility under maximum availability leaching test (95% of fly ash was dissolved), a recovery rate of 91% for Zn can be obtained using Cyanex 572, and a high adsorption rate (> 95% for both Cu and Cd) was reached using HAP for the pristine fly ash leachate. The outcomes from isothermal and kinetic study revealed that Langmuir isotherm and pseudo-second order model can well describe the Cd and Cu adsorption behavior. Economic assessment suggested that the application of HAP for the removal of Cd and Cu is a technically sound and economically feasible approach. The findings of this study demonstrated that this comprehensive process integrated leaching, solvent extraction and consequential decontamination can be a practical strategy for MSWI fly ash treatment.
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Iron-rich red mud is a potent radioactive drainage treatment material. However, the calcite in red mud attenuates its U adsorption capacity by restricting U adsorption onto adsorbent; it captures U as a dissociative complex in aqueous systems. This study produced macroporous iron and carbon combined calcined red mud (ICRM) and carbon calcined red mud (CRM) through calcination in the range of 500-800 °C. XRD results revealed that both series generated advantageous magnetite and calcite were fully decomposed. SEM and batch experiments highlighted ICRM calcined at 600 °C has more stable and favorable performance. The components of post-adsorption ICRM remained active, as demonstrated by FT-IR results. Additionally, ICRM@600 displayed superior U adsorption capacity (59.45 mg/g) than did all red mud adsorbents from our previous research. Zeta-potential results revealed ICRM has positive potential charges in acidic conditions, indicating it adsorbs U(VI) ions via electrostatic attraction. The main adsorption mechanisms of ICRM are surface electrostatic attraction, physical adsorption by porous structure, and chemical adsorption by active Al and Fe components. In application, ICRM@600 obtained a 82.20% U adsorption ratio in uranium mine pit drainage. Overall, this study offers theoretical guidances to radioactive drainage management and red mud reuse.