Selective Adsorption Of Lead Research Articles

Synthesis and characterization of MgAl- layered double hydroxide with graphene oxide intercalation: Application in lead removal from spent batteries effluent

New-energy batteries are being developed so quickly leaving behind a challenge of lead contamination from spent batteries. Many adsorbents were developed to eliminate lead from the wastewater, layered double hydroxide (LDH) is one of them. A super adsorbent Graphene Oxide (GO) intercalated MgAl-LDH (GO-LDH) was specially designed and synthesized as effective and selective lead adsorption. The GO-LDH was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM). XRD result shows an increase in d-spacing corresponding to the (003) plane of LDH. A disappearance of the COOH group stretching in the FTIR spectrum of GO-LDH was observed in the FTIR spectrum. These results confirm the intercalation of GO between the basal plane of MgAl-LDH. To fit the adsorption isotherm, the Langmuir model was utilised, yielding pseudo-second-order rate kinetics with a maximum sorption capacity of 1034 mg/g at 50 °C and pH 6.0. These findings conclude that GO-LDH could be a promising application to treat heavy metal-containing wastewater with selective adsorption of lead.

A coupling technology of capacitive deionization and carbon-supported petal-like VS2 composite for effective and selective adsorption of lead (II) ions

• ZAC@VS 2 disperses the modified tubular carbon material in VS 2 lamella. • ZAC@VS 2 has improved active sites and conductivity. • ZAC@VS 2 shows considerable specific capacitance and low charging resistance. • ZAC@VS 2 electrode displays a prominent heavy metal ions of lead (II) adsorption capacity and rate. • ZAC@VS 2 electrode has the superior ion selectivity to Pb 2+ than Fe 3+ and Na ± . The conventional separation technologies, like chemical precipitation and adsorption processes, cannot quickly and selectively separate and recycle heavy metal ions from waste. Due to its rich sulfur content and excellent electrical conductivity, vanadium disulfide is a potential material for effectively removing lead from wastewater. The vanadium disulfide material with selective adsorption ability was introduced into CDI technology to construct a coupling technology with both advantages. The N -doped modified ZIF@vanadium disulfide (ZAC@VS 2 ) composites were successfully synthesized by hydrothermal method. Electrosorption experiments show that ZAC@VS 2 material presents the remarkable saturated adsorption capacity to lead(II) ions (239.52 mg/g) in the 500 mg/L PbCl 2 solution. In the triplex blend system (Fe 3+ /Pb 2+ /Na + ) with each solute density of 100 mg/L, the saturated adsorption efficiency of 85.4% to Pb 2+ can still be maintained. In addition, compared with the Langmuir(R 2 =0.873) adsorption isotherm model, the Freundlich model (R 2 =0.922) can be better used to fit the adsorption process, which proves that the adsorption process is multilayered and heterogeneous. XPS tests and competitive adsorption experiments show that the electric double layer (EDL) and complexation together promote the selective adsorption of heavy metal ions by ZAC@VS 2 . ZAC@VS 2 composite electrode shows excellent performance in the removal of lead ions in battery waste liquid, indicating the potential of introducing ZAC@VS 2 into CDI to remove lead ions.

Selective adsorption of lead(II) from aqueous solution

ABSTRACT Adsorptive separation of Pb(II) from aqueous solution containing Pb(II) and other heavy metals (Cu(II), Zn(II) and Cd(II)) has been investigated, using three adsorbents, such as an iminodiacetic acid-chelating resin (CR11) and Fe-based adsorbents (goethite and magnetite). Batchwise adsorption of Pb(II) and other metal ions in single metal system and multi-components system was carried out with varying parameters, such as pH, time and initial concentrations of metals. CR11 possesses the highest adsorption ability for these metals, while the selectivity of individual metal is little. Goethite possesses selectivity for Pb(II) and Cu(II), and magnetite possesses selectivity for Pb(II), though the adsorption capacity for the metals is less than those with CR11. The kinetics of the adsorption of metals with all adsorbents is of pseudo-second-order, and the magnetite is revealed to have the fastest adsorption kinetics. The three adsorbents can be applied for chromatographic separation for these metals. The magnetite is feasible for selective separation of Pb(II), although complete elution cannot be achieved.

A Coupling Technology of Capacitive Deionization and Carbon-Supported Petal-Like VS2 Composite for Effective and Selective Adsorption of Lead (II) Ions

The existing separation technologies, including chemical precipitation and adsorption process, cannot quickly and selectively separate and recycle heavy metal ions of lead (II) from battery waste liquid. Due to its rich sulfur content and excellent electrical conductivity, vanadium disulfide is a potential material for effectively removing lead from wastewater. The vanadium disulfide material with selective adsorption ability was introduced into CDI technology to construct a coupling technology with both advantages. The n-doped ZIF@vanadium disulfide (ZAC@VS 2 ) composites were successfully synthesized by hydrothermal method. Electrosorption experiments show that ZAC@VS 2 material presents the remarkable saturated adsorption capacity to lead(II) ions (239.52mg/g) in the 500mg/L PbCl 2 solution. In the triplex blend system (Fe 3+ /Pb 2+ /Na + ) with each solute density of 100 mg/L, the saturated adsorption efficiency of 85.4% to Pb 2+ can still be maintained. In addition, compared with the Langmuir(R 2 =0.873) adsorption isotherm model, the Freundlich model (R 2 =0.922) can be better used to fit the adsorption process, which proves that the adsorption process is multilayered and heterogeneous. XPS tests and competitive adsorption experiments show that the electric double layer (EDL) and complexation together promote the selective adsorption of heavy metal ions by ZAC@VS 2 . ZAC@VS 2 composite electrode shows excellent performance in the removal of lead ions in battery waste liquid, indicating the potential of introducing ZAC@VS 2 into CDI to remove heavy metal ions.

Tuning of graphene oxide intercalation in magnesium aluminium layered double hydroxide and their immobilization in polyacrylonitrile beads by single step mussel inspired phase inversion: A super adsorbent for lead

• Tuning of intercalation of GO in interlayer of MgAl LDH has been demonstrated. • GO intercalated MgAl LDH incorporated polymeric beads are prepared. • Phase inversion in polydopamine restricts leaching of nanoparticles from beads. • Polydopamine modifies bead morphology favoring lead adsorption. • The composite bead exhibits superior selective adsorption for lead (209 mg/g). In the present study, graphene oxide intercalated layered double hydroxide (LDH) based adsorbent was synthesized for effective and selective adsorption of lead. Graphene oxide was intercalated in a controlled manner in the interlayer space of magnesium-aluminium layered double hydroxide which enhanced the adsorption capacity by 20% compared to pristine LDH. Effect of metal ion ratio on GO intercalation was observed. The developed nano-powder was immobilized in polyacrylonitrile beads by a single step mussel inspired phase inversion in dopamine solution. Elongated macro-voids accelerated the lead adsorption kinetics remarkably. Phase inversion in dopamine eliminated the leaching of the nanoparticles from beads. The GO intercalated LDH and the nanoparticles immobilized beads showed lead adsorption capacity of 1062 mg/g and 209 mg/g, respectively, at 323 K and pH 5.8. Adsorption isotherm showed the best fitting with Langmuir model and kinetics followed a pseudo-second order rate equation. Lead adsorption was not affected significantly by the presence of other cations, like, Ca 2+ , Mg 2+ , Fe 2+ and Zn 2+ . The bead was utilized in continuous column study and showed a breakthrough time of 35.5 h with 15 cm bed height and 10 ml/min flow rate. The bead showed good performance with real life lead containing battery effluent. The adsorbents were regenerated using 0.1(M) EDTA and reused for at least five cycles without significant reduction in lead removal efficiency. The findings of the present study suggest that the synthesized adsorbent can be used effectively for sustainable and selective adsorption of lead from real life effluent.

Selective adsorption of lead on grafted and crosslinked chitosan nanoparticles prepared by using Pb2+ as template

Poly(acrylic acid) grafted and glutaraldehyde-crosslinked chitosan nano adsorbent (PAACS) was synthesized by using Pb2+ as a template ion. The structure and morphology of PAACS were characterized by FT-IR, XRD, SEM and elemental analyses. The adsorption of PAACS for different heavy metal ions was compared and the effects of various variables for adsorption of Pb2+ were systematically studied. The results indicated that the PAACS was the aggregates of nanoparticles with the diameter of about 50–200nm and had selectivity for Pb2+ adsorption. The adsorption for Pb2+ showed a maximum adsorption capacity of 734.3mgg−1 at pH 5.0 and 303K, which was higher than in a study previously reported on ion-imprinted adsorbents. The adsorption followed the pseudo-second-order kinetics and Langmuir isotherm models. The adsorption was spontaneous and changed from chemical process into physical process when the temperature exceeded 303K. The adsorbent could be recycled with EDTA. Therefore, PAACS would be useful as a selective and high uptake nano adsorbent in the removal of Pb2+ from effluents.

Selective adsorption of lead, copper and antimony in runoff water from a small arms shooting range with a combination of charcoal and iron hydroxide

Metals and metalloids from ammunition residues at small arms shooting ranges leach into the soil and surrounding watercourses and may pose a threat to exposed wildlife and humans. To reduce the potential impact of heavy metal on the environment a field study was performed with different sorbents in order to reduce the metal concentration in polluted water from a shooting range. Two sorbents were tested in situ for their ability to reduce the concentration of Cu, Sb and Pb: Brimac® charcoal and Kemira® iron hydroxide. The mean sorption of Cu, Sb and Pb was 85%, 65%, and 88% respectively when using the charcoal and 60%, 85% and 92% respectively with the iron hydroxide. Even better sorption of the elements was achieved when the two sorbents were combined in order to increase their selectivity. The best results were achieved in the filter in which the water percolated the charcoal first and the iron hydroxide last, with a mean sorption of Cu, Sb and Pb of 89%, 90% and 93% respectively. This preparation gave a significant better sorption of Cu compared to the filter in which the water percolated the iron hydroxide first and the charcoal last. The different effect between the two filters may be due to pH, since charcoal has alkaline properties and iron hydroxide has acidic properties. For large scale experiments or in filter devices we therefore recommend use of a combination of different reactive sorbents.

Selective adsorption of lead(II) from aqueous solution by ion-imprinted PEI-functionalized silica sorbent: studies on equilibrium isotherm, kinetics, and thermodynamics

A new ion-imprinted poly(ethyleneimine)(PEI)-functionalized silica sorbents were synthesized by a hydrothermal-assisted surface grafting technique with Pb(II) as the template, PEI as the functional molecular, and epichlorohydrin as the cross-linking agent for the selective adsorption of Pb(II) from aqueous solution, and was characterized by FTIR, SEM, TGA-DTA, nitrogen adsorption, and the static batch experiment. Static adsorption experiment results showed that Pb(II)-imprinted PEI-functionalized silica sorbents had high static adsorption capacity of 60.4 mg g−1, reached an equilibrium state within 20 min, displayed stable adsorption ability for Pb(II) ions in the range of pH 4–8, had satisfactory selectivity toward Pb(II) and could be used repeatedly. Compared with Freundlich and Dubinin–Radushkevich isotherms, equilibrium data fitted to Langmuir adsorption model. The kinetic process of adsorption followed a pseudo-second-order model compared to pseudo-first-order, Elovich and intraparticle diffusion models. Negative values of ΔG° indicated spontaneous adsorption and the degree of spontaneity of the reaction increased with increasing temperature. Positive values of ΔH° showed that the adsorption process was endothermic in the experimental temperature range. The results indicated that Pb(II)-imprinted PEI-functionalized silica sorbents could be employed as an effective material for the selective adsorption of Pb(II) ions from aqueous solutions.

Selective adsorption of lead (II) ions by a manganese dioxides-loaded adsorption resin

A new adsorbent SD300-M was successfully synthesized by coating the adsorption resin SD300 with manganese oxide via KMnO4 modification. The results of X-ray photoelectron spectrometer and nitrogen adsorption measurement revealed that the manganese oxide exists as MnO2 on the surface and inside the channel of the SD300 resin. The SD300-M resin exhibited higher adsorption capacity to Pb2+ with the maximum adsorption capacity as high as 141 mg/g, comparing with original SD300 resin and the other manganese oxide-modified adsorbents, such as cellulose or carbon nanotubes. The increased adsorption of Pb2+ on the SD300-M resin arose mainly from the formation of inner-sphere complexes with MnO2. In the presence of Ca2+ and Mg2+, the SD300-M resin also has excellent adsorption selectivity for Pb2+ relative to that of the D301-M and HMO-001 resins, which arises from electrostatic interaction and surface complexation acting together. All the results indicate that the SD300-M resin is an efficient adsorbent to remove Pb2+ from aqueous solution.