Vanadium: A Review of Different Extraction Methods to Evaluate Bioavailability and Speciation

Migration of vanadium oxide nanoparticles in saturated porous media

Vanadium oxides nanoparticles (VOx-NPs) as emerging functional materials are widely applied in high-technology industries. However, their environmental behaviors remain largely known. In this study, the migration of three common VOx-NPs (V2O5, VO2, and V2O3) in saturated porous media has been investigated. V2O5 NPs showed the highest migration ability under all conditions, compared to other VOx-NPs. Increasing ionic strength and decreasing pH hindered their migration, while the presence of Ca2 + was more effective than Na+ in depositing VOx-NPs. The combined results from multiple analyses (DLVO theory, MMS equations, Traj-Hap module of Parti-Suite and HYDRUS-1D simulation) suggested that high ionic strength and low pH reduced the energy barrier between the VOx-NPs and quartz sand, and increased the particulate sizes, making VOX-NPs more difficult to migrate. Changes in VOx-NPs size effected the contribution of gravity in retention fate. Small VOx-NPs (< 400 nm) delivered to both the upstream and downstream of the quartz sand surface, while large ones (> 900 nm) remained downstream. This study provides the insight into the geochemical fates of VOx-NPs, which is helpful to develop regulating strategies to reduce/eliminate their potential environmental risks.

Hydrolysis, Ligand Exchange, and Redox Properties of Vanadium Compounds: Implications of Solution Transformation on Biological, Therapeutic, and Environmental Applications

Vanadium is a transition metal with important industrial, technological, biological, and biomedical applications widespread in the environment and in living beings. The different reactions that vanadium compounds (VCs) undergo in the presence of proteins, nucleic acids, lipids and metabolites under mild physiological conditions are reviewed. In the environment vanadium is present naturally or through anthropogenic sources, the latter having an environmental impact caused by the dispersion of VCs in the atmosphere and aquifers. Vanadium has a versatile chemistry with interconvertible oxidation states, variable coordination number and geometry, and ability to form polyoxidovanadates with various nuclearity and structures. If a VC is added to a water-containing environment it can undergo hydrolysis, ligand-exchange, redox, and other types of changes, determined by the conditions and speciation chemistry of vanadium. Importantly, the solution is likely to differ from the VC introduced into the system and varies with concentration. Here, vanadium redox, hydrolytic and ligand-exchange chemical reactions, the influence of pH, concentration, salt, specific solutes, biomolecules, and VCs on the speciation are described. One of our goals with this work is highlight the need for assessment of the VC speciation, so that beneficial or toxic species might be identified and mechanisms of action be elucidated.

Ecotoxicological, ecological, and human health risks of total carbohydrates and some inorganic pollutants on the Nile Delta region along the Egyptian Mediterranean Coast

This is one of few studies dealing with the potential impact of total carbohydrates (TCHO), and some inorganic pollutants (F, B, As, V, Se) on human health. Additionally, the latter pollutants toxicological and ecological effects on the Egyptian Mediterranean Coast, especially, the Nile Delta region, were investigated. Both F (0.18 ± 0.09 mg/g) and As (2.47 ± 5.39 μg/g) were of lower concentrations compared to previous reports. Values of all ecological and ecotoxicity indices, particularly, the risk quotient (RQ), showed that arsenic had the most adverse biological effects on three trophic levels (algae, invertebrates, and fish). Children and adults non-carcinogenic hazard index (HI) values were <1, revealing that sediments in the studied area would pose no risk to humans. However, arsenic carcinogenic risk (CR) values exceeded the maximum permissible limits, implying risk to children and adults. These findings could anticipate toxic impacts of polluted effluents on the Nile Delta region.

Vanadium extraction from steel slag: Generation, recycling and management

The metal vanadium has superior physical and chemical properties and has a wide range of applications in many fields of modern industry. The increasing demand for vanadium worldwide has led to the need to guarantee sustainable vanadium production. The smelting process of vanadium and titanium magnetite produces vanadium-bearing steel slag, a key material for vanadium extraction. Herein, vanadium production, consumption, and steel slag properties are discussed. A detailed review of methods for extracting vanadium from vanadium-bearing steel slag is presented, including the most commonly used roasting and leaching method, and direct leaching, bioleaching and enhanced leaching methods are also described. Finally, the rules and regulations of steel slag management are introduced. In general, it is necessary to further develop environmentally friendly vanadium extraction methods and technologies from vanadium containing solid wastes. This study provides research directions for the technology of vanadium extraction from steel slag.

Metformin ameliorates vanadium pentoxide or gamma irradiation-stimulated hepatotoxicity in male rats via targeting endoplasmic reticulum stress-induced apoptosis

INTRODUCTION

This work aims to validate the ameliorative influence of metformin against endoplasmic reticulum stress (ERS)-prompted apoptosis caused by vanadium pentoxide (V2O5) or gamma-irradiation (γ-irradiation) in hepatic tissues of male rats.

METHODS

There were six groups of rats: the control, metformin (100 mg/kg body weight, i.p.), V2O5 (12.5 mg/kg body weight, i.p), V2O5 plus metformin, γ-irradiation group (acute dose 6 Gy), and γ-irradiation plus metformin; for 2 weeks. Hepatic malondialdehyde (MDA) and reduced glutathione (GSH) levels were evaluated. Additionally, the protein expression of certain endoplasmic reticulum stress-related (ERS) biomarkers; Inositol requirement enzyme 1α (IRE1α), TNF receptor-associated factor 2 (TRAF2), and Apoptosis signal-regulating kinase 1 (ASK1); were estimated in hepatic tissues. Moreover, apoptosis-associated biomarkers; Bax, Bcl-2, caspase-3 and HSP70 levels have been assessed. Furthermore, histopathological changes in hepatic tissues were observed.

RESULTS

Metformin with V2O5 or γ-irradiation significantly decreased MDA, IRE1α, TRAF2, ASK1, Bax, and caspase-3 compared with V2O5 or γ-irradiated groups. Meanwhile, it significantly elevated GSH, Bcl-2, and HSP70 levels compared to exposure to V2O5 or γ-irradiation groups. Interestingly, the obtained results concur well with histological alterations.

DISCUSSION

Our findings demonstrate the protective influence of metformin against ER stress-induced apoptosis through enhancing GSH and reduction of ERS and apoptosis suggesting that metformin may have positive impacts as a potential radiation protector beyond its glucose-lowering effect.

Spatiotemporal characterization of vanadium at the sediment-water interface of a multi-ecological lake

As an emerging environmentally harmful metal, vanadium (V) deserves significant research attention due to its hazardous concentrations in aquatic environments. However, the research on the characterization of V in sediment-water interface (SWI) remains limited. In this study, seasonal sampling was conducted in algal- and macrophyte-dominated zones via the method of in situ high-resolution diffusive gradients in thin films (DGT). The concentration of dissolved V in water in algal-dominated regions (12 sites) exceeded the long-term ecotoxicology limit of 1.2 μg⋅L-1. Seasonal variations of chemical speciation of V were observed in three ecological sites. DGT-labile V at the SWI exhibited two basic patterns associated with eutrophic status, one showing sharply decreasing gradients in the vicinity of the SWI and the other showing the absence of diffusion gradient. Positive correlations were observed between the water-dissolved V and the DGT-labile V, indicating DGT-labile V is a sensitive indicator for the release of V from sediment into water. Moreover, the mobility of V was influenced by the reduction of Fe(hydr)oxides and complexation with organic matter, in particular, during periods of algal blooms. It is suggested that V contamination at the SWI of algal-dominated zones deserves additional attention.

Cyanobacterial blooms increase the release of vanadium through iron reduction and dissolved organic matter complexation in the sediment of eutrophic lakes

Vanadium (V), a hazardous environmental contaminant, can be highly toxic to aquatic or even human life. Nonetheless, knowledge of its redox geochemistry and mobility in sediments, especially those of eutrophic lakes, remains limited. In this study, we combined in situ high-resolution sampling and laboratory simulation experiments for monitoring soluble and labile V to reveal the mobilization mechanism of V in the sediment of Lake Taihu. The results showed that the concentration of soluble V (1.18-5.22 µg L-1) exceeded the long-term ecotoxicology limitation proposed by the government of the Netherlands. The highest value appeared in summer (July to September), with an average concentration of 3.87 µg L-1, which exceeded the short-term exposure limit. The remobilization of V in summer was caused by the combined effect of the reduction of Fe(hydr)oxides and dissolved organic matter (DOM) complexation, which accelerated the release of associated Fe-bound V and increased the solubility of DOM-V. Additionally, V showed high mobility in winter, owing to the species of V(Ⅲ)/V(Ⅳ) being oxidized to V(Ⅴ) with higher solubility. It is noteworthy that the elevated remobilization of V in sediments increases the risk of V release from sediments, which poses the threat of water V pollution in Lake Taihu.

Soil amendments for vanadium remediation: a review of remediation of vanadium in soil through chemical stabilization and bioremediation

Immobilization of vanadium (V) in soils is one option to prevent groundwater contamination and plant uptake. Phytoremediation, microbial remediation, and chemical stabilization using soil amendments are among the leading environmentally friendly and economically feasible techniques in V remediation. Soil amendments were used to reduce V mobility by immobilizing it in the soil matrix through chemical stabilization, while bioremediation methods such as phytoremediation and microbial remediation were used to remove V from contaminated soils. Vanadium exists in several species and among them V5+ species are the most prevalent, toxic, and soluble form and present as a negatively charged ion (H2VO4- and HVO42-) in oxic soils above pH 4. Amendments used for chemical stabilization can change the physicochemical properties enhancing immobility of V in soil. The pH of the soil environment, point of zero charge of the colloid surface, and redox conditions are some of the most important factors that determine the efficiency of the amendment. Commonly used amendments for chemical stabilization include biochar, zeolites, organic acids, various clay minerals and oxides of elements such as iron, titanium, manganese, and aluminum. For bioremediation, chelating agents and microbial communities are used to mobilize V to enhance phyto-or microbial-extraction procedures. The objectives of this review were to discuss remediation methods of V while considering V speciation and toxicity in soil, and soil amendment application for V removal from soil. The information compiled in this review can guide further research on soil amendments for optimal V remediation in largely contaminated industrial sites.

Vanadium Contamination in Soil and Atmospheric Deposition in Albania

By examining and evaluating the vanadium content in topsoil and moss samples, this study sought to better understand vanadium contamination in soil and atmospheric deposition. In the research area, Hypnium cupressiforme sps. moss is used. According to different distribution patterns and the lack of a link between vanadium in moss and soil samples studied by correlation analysis, no interactions between substrate soil and moss samples were investigated. Maximum vanadium concentrations (13.2 mg/kg and 250 mg/kg, respectively) were found in both moss and soil samples near the Cu mineral-rich Gjegjan area. Using lithium-normalized data on vanadium, the effect of anthropogenic activity on the vanadium in moss and soil samples is examined. There were no relationships between concentration and normalized data in moss and soil samples, showing the simultaneous effects of natural and anthropogenic sources of vanadium in the research area. Country-specific trends revealed no change for vanadium since 2010 in Albania.