Removal Of Vanadium Research Articles

Simultaneous removal of vanadium and nitrogen in two-stage vertical flow constructed wetlands: Performance and mechanisms

Vanadium (V(V)) and nitrate, as co-concomitant pollutants in water bodies, pose potential threats to the eco-environment and human health. This study was to reveal the feasibility of simultaneous removal of V(V) and nitrate in the series-wound vertical flow constructed wetlands (CWs) with iron ore (B-CWs)/manganese ore (C-CWs)-wood substrates. The results showed that B-CWs could achieve efficient V(V) and NO3−-N removal with the influent of 2 and 10 mg/L (V(V)/NO3−-N = 1:5), respectively. With the increase of V(V)/NO3−-N ratio (V(V)/NO3−-N = 1:1), B/C-CWs exhibited better combined pollution removal. Even when nitrate was removed (V(V)/NO3−-N = 1:0), the systems could maintain a good capacity for V(V) removal. High V(V) (20 mg/L) significantly inhibited V(V) removal, with a slight recovery of the performance as the decrease of V(V) influent. High NO3−-N concentration (10 mg/L) effectively enhanced V(V) removal and restored C-CWs to the better level. V(IV) precipitates/oxides were the main reducing end-products. High abundance of V(V)-reducing bacteria and iron/manganese cycling pumps ensured efficient V(V) removal.

Toward Finding the Role of Surface Iron Ions in Enhancing Oxygen-Evolution Reaction.

The oxygen evolution reaction (OER) in alkaline media is crucial for energy conversion technologies, and Fe-based catalysts have garnered significant attention for their efficacy. In this study, we provide an investigation of Fe-based catalysts under OER conditions using some techniques. Our findings reveal minimal structural alterations in the bulk FeHxOy framework during OER, indicating that the bulk structure remains largely intact. Instead, the catalytic activity is primarily localized on the material's surface. This conclusion is corroborated by the measured low electrochemical surface area (ECSA) of FeHxOy, suggesting that its limited OER performance stems from a paucity of active sites rather than low intrinsic activity. The superior efficiency of Fe ions in conductive oxides or on conductive metal substrates (e.g., copper and gold) in OER is attributed to the increased availability of surface-active sites in these systems. To further elucidate this phenomenon, we investigated two additional systems: NiFe and VFe (hydr)oxides. For NiFe (hydr)oxides, we demonstrate that only surface Fe ions contribute actively to OER. In contrast, in VFe (hydr)oxides, the removal of vanadium resulted in a marked increase in ECSA and the generation of defect sites, significantly enhancing OER activity. These findings provide critical insights into the surface-specific role of Fe ions in catalytic activity and could inform future design strategies for more efficient OER catalysts by optimizing the availability and reactivity of surface-active Fe sites.

Recovery of vanadium element from wastewater of petroleum refineries using effective adsorbent: Mathematical approach via isothermal, kinetics and thermodynamic simulation

Adsorption behavior can be determined using different essential studies such as adsorption isotherm, kinetics, and thermodynamics. In this study, adsorption isotherm models, and kinetic, and thermodynamics studies are used to describe the use of alumina as an effective adsorbent and a remover of vanadium (V+5) ions from aqueous solutions contaminated by this metal. The aqueous solutions used simulate the wastewater of most traditional oil refineries. Efficiency can be determined by comparing the correlation coefficients of the linear relationships used with each model. Using alumina, the perfect removal of vanadium ions was achieved. Vanadium removal increases with an increase in the operating conditions, which are time temperature, agitation speed, pH, and adsorbent’s media dose. However, it also increases with the elimination of the initial concentration. This study shows that the vanadium’s adsorption based on the Langmuir isotherm model gives a correlation coefficient of 0.9999, while when it is based on the Temkin and Freundlich isotherms the correlation coefficient is less. Hence, adsorption on the surface of alumina takes place in monolayer surfaces with a regular distribution of particle’s binding energy and a narrow quantity of identical sites on the surface of alumina. Subsequently, the kinetic study shows that the adsorption behavior matched the pseudo-second-order kinetic model with R2 equaling 0.9999. Also, thermodynamics studies approves that the adsorption is a spontaneous endothermic process of enthalpy change.

Investigation into the effects of Na2B4O7 on the removal of titanium and vanadium from aluminium matrix

ABSTRACT This study proposes a method of adding Na₂B₄O₇ to remove titanium and vanadium impurities from primary aluminium. The effect of Na₂B₄O₇ to the aluminium melt on the removal of titanium and vanadium impurities was investigated, with a focus on the influence of varying addition amounts and holding times. According to the results, the chemical reaction occurring within the melt was postulated and a thermodynamic calculation was conducted. At 750°C and holding times of 30 min, the impurity contents of titanium and vanadium gradually decrease with an increase the amount of Na₂B₄O₇. At an addition of 0.8 wt.%, the removal rates were observed to be 53.3% and 76.3%, respectively. The impurity removal effect exhibited a positive correlation with the holding times. Holding for 90 min, the content of titanium and vanadium impurities decreased from 15 and 97 ppm to 1 and 6 ppm, with removal rates of 93.3% and 93.8%, respectively. Thermodynamic calculation results indicate that B undergoes spontaneous reaction with titanium and vanadium, forming TiB₂ and VB₂, which precipitate at the bottom, thereby explaining the observed decrease in impurities. This study provides ideas and data reference for the removal of titanium and vanadium impurities in aluminium matrix.

Investigation of demetallization of Ni and V in crude oil using spherical polyelectrolyte brushes with adjuvant

Nickel and vanadium in crude oil adversely affects the quality of petroleum coke and refining process. Polymer brushes bearing high-density ligands have shown promising nickel removal ability. In this work, submicron polybutadiene (PB) grafted by aminodithio- carbamate acrylamide (PAMDTC@PB) was prepared and characterized by the infrared spectroscopy, dynamic light scattering, and elemental analysis. Based on results of molecular simulation, PAMDTC was selected as ligand molecule at first. Then the nickel and vanadium removal rates by PAMDTC@PB and traditional polyacrylic acid brushes (PAA@PB) were evaluated through the electric desalination process, both in the model and real oil samples. The result shows that S atom in AMDTC is most likely to chelate with metal porphyrin compounds and AMDTC molecule presents highest chelating activity. Compared with PAA@PB, the removal rate of Ni and V porphyrin compounds with the aid of PAMDTC@PB increases significantly, with an optimized removal rate of 46.91 % and 56.81 %. To achieve better metal removal efficiency and higher utilization rate of prepared polymer brushes, sodium dimethyl dithiocarbamate (SDD) is introduced into the electric desalination process as a adjuvant. The results indicate that the addition of SDD leads to a increment of 10–30 % to the removal rate of Ni and V and a reduction of brush dosage by 200–400 ppm in the electric desalination process, exhibiting great potential of industrial applications of novel desalination process with adjuvant.

A sustainable bioremediation of vanadium from marine environment and value-addition using potential thraustochytrids

Rising concerns about global environmental degradation underscore the pressing need for effective solutions to combat heavy metal pollution. Industries such as semiconductor and steel production discharge vanadium into marine ecosystems, posing significant risks to both marine life and human health. The current study investigates efficacy of utilizing marine thraustochytrid for efficient vanadium removal outcompeting other microbial sources. By optimizing pH and temperature conditions during harvesting, achieved a remarkable 50.80 % enhancement in vanadium removal efficiency, from 19.31 to 29.12 mg/L. Furthermore, chelating agents EDTA and citric acid supplementation demonstrated promising enhancements, reaching up to 31.21 and 32.59 mg/L, respectively. Notably, vanadium-treated biomass supplemented with citric acid exhibited maximum enhancement in lipid content, from 58.47 to 75.34 %, indicating thraustochytrid’s potential for biofuel production. This study presents a sustainable approach for industrial-scale vanadium bioremediation, aligning with Sustainable Development Goals focused on dual benefits of environmental protection and renewable energy.

Insights into vanadium removal performance and mechanism in aqueous solution by one-step pyrolysis prepared Phytolacca acinosa biochar composite

Iron-loaded biochar (FBC) was synthesized via the dry-mixed co-pyrolysis of Phytolacca acinosa, Fe2(SO4)3 and NaOH and then used to remove aqueous vanadium (V (V)). FBC demonstrated the optimal adsorption performance for V (V) (57.67 mg/g) due to the loading of iron oxide, which increased the number of oxygen-containing functional groups. The adsorption of V (V) on FBC was pH-dependent, and the adsorption rate was high in the pH range of 2–8. Common cations and anions in water did not affect the adsorption of V (V) onto FBC, while NH4+, Na+, Ca2+, and Cd2+ can promoted its adsorption. The adsorption mechanism of FBC mainly included chemical adsorption, electrostatic adsorption, oxygen-containing functional group complexation and ion exchange. The easy preparation method, high adsorption capacity and adaptability makes FBC an ideal material for removing V (V) from wastewater.

Deep-sea microorganisms-driven V5+ and Cd2+ removal from vanadium smelting wastewater: Bacterial screening, performance and mechanism

The disorderly discharge of industrial wastewater containing heavy metals has caused serious water pollution and ecological environmental risks, ultimately threatening human life and health. Biological treatment methods have obvious advantages, but the existing microorganisms exhibit issues such as poor resistance, adaptability, colonization ability, and low activity. However, a wide variety of microorganisms in deep-sea hydrothermal vent areas are tolerant to heavy metals, possessing the potential for efficient treatment of heavy metal wastewater. Based on this, the study obtained a group of deep-sea microbial communities dominated by Burkholderia-Caballeronia-Paraburkholderia through shake flask experiments from the sediments of deep-sea hydrothermal vents, which can simultaneously achieve the synchronous removal of vanadium and cadmium heavy metals through bioreduction, biosorption, and biomineralization. Through SEM-EDS, XRD, XPS, and FT-IR analyses, it was found that V(V) was reduced to V(IV) through a reduction process and subsequently precipitated. Glucose oxidation accelerated this process. Cd(II) underwent biomineralization to form precipitates such as cadmium hydroxide and cadmium carbonate. Functional groups on the microbial cell surface, such as -CH2, C=O, N-H, -COOH, phosphate groups, amino groups, and M-O moieties, participated in the bioadsorption processes of V(V) and Cd(II) heavy metals. Under optimal conditions, namely a temperature of 40 °C, pH value of 7.5, inoculation amount of 10%, salinity of 4%, COD concentration of 600 mg/L, V5+ concentration of 300 mg/L, and Cd2+ concentration of 40 mg/L, the OD600 can reach its highest at 72 h, with the removal efficiency of V5+, Cd2+, and COD in simulated vanadium smelting wastewater reaching 86.32%, 59.13%, and 61.63%, respectively. This study provides theoretical insights and practical evidence for understanding the dynamic changes in microbial community structure under heavy metal stress, as well as the resistance mechanisms of microbial treatment of industrial heavy metal wastewater.

Green biopolymer stabilizer induced robust removal of vanadium (V) by sulfidated microscale zerovalent iron

The in situ remediation of V(V) pollution in groundwater by the sulfidated microscale zero-valent iron (S-mZVI) is promising, while the practical application of S-mZVI faces a great challenge due to its gravitational sedimentation. Herein, we proposed an effective and environmentally friendly strategy to stabilize S-mZVI using xanthan gum (XG), and elucidated the mechanisms focused on the XG-induced stabilization, the removal of V(V) by S-mZVI and XG composites (S-mZVI@XG), and the XG-enhanced removal of V(V). First, S-mZVI@XG was fabricated with various XG concentrations, and the characterization confirmed the presence of the adsorbed and dispersed XG. Then, the stability of S-mZVI@XG was tested. It was found that as XG increased, the stability of S-mZVI@XG was improved due to electrostatic repulsion and steric-hinerance effect. Specifically, the settlement of S-mZVI@XG5 (XG = 5.0 g·L-1) was not found, and by contrast, more than 87.0 % of S-mZVI settled in 10 min. Finally, the application of S-mZVI@XG towards V(V) removal was studied. The results showed that the removal rate of V(V) reached 95.2 % by S-mZVI@XG5, greater than that by pristine S-mZVI (64.0 %). The reduction of V(V) to V(IV) and V(III) by Fe0, Fe2+, and S2- and the precipitation were major removal mechanisms. In addition, the XG-enhanced removal of V(V) was mainly ascribed to the stabilization and synergistic effects. These findings provided mechanical and technical insights into the practical application of stabilized S-mZVI for remediation of V(V) pollution in groundwater.

Ultrasound enhances the removal of V5+ in wastewater by ball-milled zero-valent iron: Effects and mechanisms

Vanadium is considered to be a harmful industrial pollutant that poses a serious threat to health. In this study, the effect of ultrasonic-enhanced ball milling zero-valent iron removal of vanadium in wastewater was investigated and the basic mechanism of this process was elucidated. The results of the study confirmed that the ultrasonic intervention significantly accelerated the vanadium removal rate and greatly shortened the time required to achieve equilibrium. Under certain experimental conditions, the removal efficiency of vanadium under ultrasonic conditions is 99.1 %, which is 1.4 times higher than that of the traditional constant-temperature water bath device (70.86 %). Analytical techniques such as electron paramagnetic resonance (EPR) and ultraviolet (UV) spectroscopy have confirmed that ultrasonic-induced cavitation and microjet phenomena actively stimulate the formation of more H radicals and Fe2+. The key role of Fe2+ in the removal reaction was further explored and confirmed by a quenching experiment. Through fitting the experimental data of different isothermal adsorption models and reaction kinetics, it is concluded that the adsorption process conforms to the pseudo-second-order kinetics and the Langmuir isothermal model. The adsorption process is dominated by chemisorption, and the maximum adsorption capacity is 153.033 mg·g−1. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and other analyses show that under the action of ultrasonic waves, V5+ is rapidly reduced to its lower oxidation state through reduction within the first 10 min of the reaction. Secondly, as the reaction progresses and the pH value increases, electrostatic adsorption and coprecipitation are involved in the removal reaction.

Improving vanadium removal from contaminated river water in constructed wetlands: The role of arbuscular mycorrhizal fungi

Industrial activities pose a significant ecological risk to water resources as they pollute surrounding waters with vanadium (V). Although the contribution of plants and substrates to V removal in constructed wetlands (CWs) has been reported, the role of arbuscular mycorrhizal fungi (AMF) is unclear. The aim of the present study was to investigate the role of AMF in V removal in CWs and to elucidate the underlying mechanisms. Reed plants (Phragmites australis) were inoculated with an AMF strain (Rhizophagus irregularis) in CW columns, creating AMF-inoculated (+AMF) and non-inoculated (-AMF) treatments. Three levels of influent V concentrations (low: 0.50 mg L−1, medium: 1.14 mg L−1 and high: 1.52 mg L−1) were examined. The + AMF treatment showed higher V removal (60%–98%) than the control (40%–82%) in all three conditions, although the difference was not significant in some cases. The mean mycorrhizal effects were 75%, 19%, and 28% for low, moderate, and high influent V concentrations, respectively. The +AMF treatment showed a higher GRSP-bonded V concentration (5.5 mg g−1) than the -AMF treatment (4.0 mg g−1). Furthermore, +AMF treatment showed larger plants with higher V concentrations in their tissues, accompanied by increased biological concentration factors and biological accumulation factors. Given the remarkable positive effect of AMF on V removal, our study suggests that treating AMF in CWs is a worthwhile approach.

Investigating the Absorption of Quaternary Ammonium Salt-Functionalized Silica Towards Vanadium in Hydrochloric Acid Solution

ABSTRACT A quaternary ammonium salt-functionalized silica based on N-benzyl-N-methylethanolamine (BMEA-SD) was prepared for the removal and recovery of pentavalent vanadium [V(Ⅴ)] from hydrochloric acid solutions. The impact of pH, contact time, ionic strength, competitive metal ions, and recyclability of the adsorption factors were investigated. The results showed that BMEA-SD was an effective V(Ⅴ) adsorbent with a maximum adsorption capacity of 51.42 mg g−1 at solution pH 3, contact time of 30 minutes, and temperature of 298 K. Characterization of BMEA-SD materials by TG, FTIR, SEM, and XPS. In addition, the adsorption kinetics followed a pseudo-second-order model, with film diffusion being the determined step. The Langmuir isotherm suggested that monolayer chemical adsorption occurred on the adsorbent surface, and thermodynamics data indicated that the V(Ⅴ) adsorption process was spontaneous and endothermic. Selective separation studies (βV/Cr = 109.87, βV/Mn = 1171.40) highlighted its potential for selective adsorption of V(Ⅴ) over hexavalent chromium [Cr(Ⅵ)] and divalent manganese [Mn(II)]. Desorption was most effective using HCl aqueous solution, and this material maintained good adsorption capacity after five cycles. The experimental results indicated that the adsorption behavior might stem from the interplay of electrostatic forces, redox transformations, and ligand-exchange. This investigation revealed the potential of the adsorbent as a promising, efficient, and renewable for enriching and recovering V(Ⅴ) ions from hydrochloric acid solution.

Designing of functional zirconium silicates for vanadium ions recovery from model and real wastewaters

The efficient removal of vanadium(V) from model and real wastewaters by using adsorption is challenging due to the different oxidation states of this element. To address this problem, three adsorbents with different functionalities – ZrO2, ZrO2–SiO2, and ZrO2–SiO2–NH2 – were prepared via in situ sol-gel synthesis. To optimize the adsorption process conditions, different pH values, adsorbate concentration, adsorbent mass, temperature, and phase contact time, were evaluated, and the results of static experiments were presented. Furthermore, to describe the process in detail, commonly known kinetic, equilibrium as well intraparticle diffusion models were applied and analyzed. A kinetic study showed that V(V) removal occurred quickly and reached a level higher than 90% within 30 min when ZrO2–SiO2–NH2 was used. What is more, it was demonstrated that the ZrO2–SiO2–NH2 adsorbent exhibited the best properties and capacity in V(V) sorption, with maximum sorption (89.31 mg/g) achieved at optimum process conditions. The prepared adsorbents were thoroughly evaluated in terms of chemical composition, surface nature, morphology and structural properties. The incorporation of vanadium ions into the surface of ZrO2–SiO2–NH2 was proved and the mechanism of adsorption was proposed. The obtained results provided the high potential of the synthesized zirconium silicates in the uptake of vanadium ions from model and real wastewaters, and may open up new possibilities for the design of effective wastewater treatment methods.

Syringe-based microextraction for the removal of vanadium from different water and food samples using newly synthesized imino diacetate functionalized polystyrene as a new adsorbent: A multivariate approach

In this work, a new imino diacetate functionalized polystyrene (PS-Plina-ida) was synthesized and used as adsorbent for the removal of vanadium. The long narrow column solid phase microextraction connected to the portable syringe (LCSPME-PSS) system consists of a microextraction column filled with a solid phase material, a syringe, and a connecting tube. The microextraction column is made of a long and narrow glass column filled with a solid phase material (PS-Plina-ida) that selectively binds the target analyte. The syringe is used to aspirate the sample into the microextraction column and to elute the extracted analyte into the syringe for analysis. SEM, 1HNMR, DSC, and FTIR techniques were used to characterization of PS-Plina-ida. The key variables such as pH, amount of PS-Plina-ida, the concentration of vanadium, and adsorption cycle (min) of the proposed method were studied by using RSM of the design of the experiment under the desired condition. The experimental data was checked by using various isothermal models to check their adsorption behavior. Kinetic and thermodynamic studies were also carried out. When the analytical competence was tested, a linear response with (r) 0.989 for ranges of 0.50 and 10 mg/L was observed. A low limit of detection (30 ng/L) and a high enhancement factor (100) were obtained. Different real samples (water and digested food) were used to evaluate the practical application of the reported method.

Superior Removal of Vanadium(V) from Simulated Groundwater with a Fe-Based Metal-Organic Framework Immobilized on Cotton Fibers.

A suitable adsorbent is essential in the process of removing hazardous vanadium(V) from actual groundwater. In this work, MIL-88A(Fe)/cotton (MC) was employed to eliminate V(V) from simulated vanadium-contaminated groundwater. The findings demonstrated that MC exhibited an exceptional performance in removing V(V), displaying a maximum adsorption capacity of 218.71 mg g-1. MC exhibits great promise as an adsorbent for V(V) elimination in an extensive pH range spanning 3 to 11. Even in the presence of high levels of competing ions such as Cl-, NO3-, and SO42-, MC demonstrated remarkable specificity in adsorbing V(V). The results of column experiments and co-occurring ions influence tests indicate that MC is a potential candidate for effectively treating actual vanadium-contaminated groundwater. The effluent could meet the vanadium content restriction of 50 μg L-1 required in China's drinking water sources. Regeneration of MC can be performed easily without experiencing significant capacity loss. The results obtained from this research indicate the promising potential of MC in mitigating vanadium pollution.

Vanadium removal and floc characteristics of tannin biocoagulants and iron sulphate in the treatment of mine effluent

This study compared the performance of tannin (quebracho and spruce) and iron sulphate (FS) coagulants for the removal of vanadium from effluent derived from an abandoned vanadium mine. The efficacy of the materials was studied at the natural pH of the mine effluent (7.4), and at adjusted pH levels of 4 and 9. The quebracho tannin coagulant (QT) recorded impressive turbidity and vanadium removals of above 88% over a wide pH range. However, the spruce tannin coagulant (ST) was not as effective at pH 9 (39%) although it showed an improved vanadium removal of 46% and 70% at pH 7.4 and 4, respectively. This was attributed to the lower charge density of ST than that of QT, and to a loss of cationic properties at pH 9. FS performed better in terms of vanadium removal (pH 4: 86%, pH 7: 98%, pH 9: 100%) with lower coagulant doses, although effective turbidity removal required precise pH control. QT produced the largest flocs and the highest floc regrowth at pH 4 and 7. Under alkaline conditions, tannin coagulants exhibit no regrowth, which implies that a careful flocculation and floc separation step is needed. The natural organic matter fractionation results revealed that FS effectively removed hydrophilic carbon (76%) in a pH-controlled mine effluent better than tannin coagulants (QT: 12% and ST: 22%) from the pH 4 effluent; however, ST removed hydrophobic carbon entirely. All coagulants adequately removed humic substances, with FS being the most efficient (88%), followed by ST (53%) and QT (47%). X-ray photoelectron spectroscopy (XPS) analysis of jar test residues showed that some of the vanadium removed existed in the V(IV) oxidation state.

Estimation of vanadium removal from calcification roasting-acid leaching tailings using ultrasonic-H2C2O4 synergistic technology

Metal vanadium smelting produces roasting-acid leaching tailings containing approximately 1% vanadium residue, making it challenging to store and recycle these waste tailings in an environmentally friendly manner. To address this issue, a clean method called ultrasonic-enhanced oxalic acid complexation was proposed in this study for efficient removal of residual vanadium. Under the optimal conditions, the removal rate of vanadium and the decomposition rate of oxalic acid reached 86.88% and 23.6%. An in-depth analysis on the experimental results in combination with thermodynamics found a virtuous cycle chain induced by ultrasonic cavitation. Ultrasonic waves facilitated the decomposition of oxalic acid, producing more CO2 to supplement the limited cavitation bubble nucleuses. Consequently, the cavitation effect was strengthened, leading to an increased yield of OH radicals. This resulted in a continuous improvement in the oxidation environment. Furthermore, the enhanced virtuous cycle generated by ultrasonic cavitation produced powerful microjets that facilitated the stripping and dispersion of mineral particles. Overall, the oxalic acid-ultrasonic leaching technique offers a clean and efficient technology for separating vanadium.

Unraveling the enhancement of sulfidation on microscale zerovalent iron toward removal of vanadium(V) from groundwater

Sulfidation has been regarded as an effective strategy to enhance the sequestration of contaminants by zerovalent iron (ZVI). However, the effect of sulfidation on ZVI for V(V) removal has not been explored, and the mechanism has not been fully elucidated. Here, this study evaluated V(V) removal by sulfidated microscale ZVI (S-mZVI) and sufficiently ascertained its underlying mechanism. First, the sulfidation of mZVI was studied and the characterization confirmed a uniformly-distributed FeSx shell fabricated on mZVI. Then, applying S-mZVI for V(V) removal was tested as a function of S/Fe molar ratios, pH, dissolved oxygen, and common anions. The greatest removal (98.1%) of V(V) was achieved by S-mZVI prepared under S/Fe of 0.05, 98 times higher than that by mZVI. The decreased pH showed a positive effect and V(V) removal reached 100% at pH 3.0. The common anions (Cl−, SO42−, NO3− and HCO3−) showed slight inhibition on V(V) removal. Finally, V(V) removal by S-mZVI was clarified to be mediated via a combined function of reduction from V(V) to V(IV) and V(III), adsorption, and precipitation. These findings provided valuable insights into applying ZVI materials for V(V) removal.

Advanced strategies for effective treatment of vanadium (III) polluted water by potential microalgae

BackgroundEnvironmental concerns are escalating globally due to rising pollution, with heavy metals like vanadium posing health risks even at 2 ppm. Industries like steel and semiconductors discharge vanadium, presenting environmental hazards. However, there's a lack of sustainable treatment methods for vanadium removal. This study aims to develop an eco-friendly microalgae vanadium treatment while utilizing microalgal biomass for biofuels, offsetting treatment expenses. MethodsPotential microalgae is chosen for vanadium (III) treatment. Over an 18-days period, maximum V(III) removal was aimed with adequate biomass and lipid yields. pH and temperature optimization enhances vanadium removal, guided by zeta potential analysis. FTIR confirms vanadium adsorption via algal cell wall reactive groups. Significant FindingsThe study demonstrates a viable solution for the pressing issue of vanadium pollution. Chlorella sorokiniana TU5 effectively removes V(III), achieving a substantial removal rate of 20.38 mgL−1. Moreover, the generated microalgal biomass showed a biomass yield of 2.3 gL−1 and a lipid yield of 577.3 mgL−1. The strategic optimization of pH and temperature further enhances the vanadium removal capacity. This approach not only addresses vanadium pollution but also provides a sustainable route for biofuel production using microalgal biomass, positioning it as a promising technique for industrial-scale vanadium bioremediation.

Pilot-scale vanadium adsorption onto in-situ biogenic amorphous ferric hydroxide

In order to reach 4 μg l−1 vanadium in drinking water adsorption onto in-situ biogenic amorphous ferric hydroxide (AFH) is identified as robust new treatment. The evaluation of its technical feasibility and robustness was the aim of this study. As approach at pilot-scale, Fe(II) and oxygen was dosed before pilot waterworks and Fe(II) subsequently biotically oxidized and precipitated in a filter bed. The so in-situ generated biogenic AFH served as adsorbent for vanadium removal. Results show that an initial vanadium concentration of 30 μg l−1 was removed to below 4 μg l−1, if at least 3 mg l−1 Fe(II) were dosed, resulting in a loading of 8.7 mg V per g AFH. A vanadium concentration of 60 μg l−1 with a dosage of 3 mg l−1 Fe(II) was the upper limit for sufficient removal. Vanadium removal increased with increasing pH in the technical setup, due to faster oxidation of Fe(II) in the supernatant, even though adsorption capacity of AFH decreases with increasing pH. A filtration velocity of 20 m h −1 represented the highest velocity to undercut 4 μg l−1 vanadium in the effluent. By mixing Fe(II) containing groundwater with oxygen and vanadium containing water prior to an adsorption filter with AFH sufficient removal was reached, however dependent on the resulting Fe(II) concentration.