Adsorptive Removal Of Lead Ions Research Articles

Biological synthesis of bimetallic hybrid nanocomposite: A remarkable photocatalyst, adsorption/desorption and antimicrobial agent

Herein bimetallic nanocomposites Ag with nickel and cobalt were synthesized by using the extract of W. coagulans. Nanocomposites synthesis were confirmed by using UV-Visible at 430 nm for and 504 nm for Ag@Ni and Ag@Co respectively. From XRD technique it was established that nanocomposites have crystalline nature and face-centered cubic structure. A strong antibacterial behavior toward Gram-positive Bacteria Staphylococcus aureus with 48.9% and 32.1% inhibition for Ag@Co and Gram-negative bacteria E. coli with 33.1% and 25.7% inhibition zone were observed for Ag@Ni respectively. Next the composites exhibited electrifying 90.2% and 82% degradation for Ag@Co and Ag@Ni against methyl orange (MO) through photocatalysis. Furthermore, Ag@Ni and Ag@Co nanocomposites showed efficient adsorption capacity of heavy metal (lead) at pH 7 within 45 min and 90% for adsorptive removal of lead ions from water with significant antioxidant potential. The current finding suggested, silver-based nanocomposites as an appropriate and promising candidate for efficient adsorptive and catalytic potentials removal of toxic pollutants.

Ethylenediaminetetraacetate functionalized MgFe layered double hydroxide/biochar composites for highly efficient adsorptive removal of lead ions from aqueous solutions.

The application of layered double hydroxides (LDHs) of MgFe and its composites with biochar of Eucalyptus camdulensis (Eb) and ethylenediaminetetraacetic acid (EDTA) was explored in a batch study to mitigate toxic lead ions (Pb2+) from synthetic wastewater solutions. SEM images revealed that MgFe/LDH composites with Eb were successfully formed, while FTIR spectra confirmed the successful adsorption of Pb2+ onto the MgFe/LDH and composite adsorbents. Batch equilibrium was attained after 60 min, then the adsorption capacity gradually increased. An increase in adsorption capacity (and a 60% decrease in the percentage removal) was observed by increasing the initial Pb2+ concentration, and the highest value was 136 mg g-1 for MgFe/LDH-Eb_EDTA. A 50–60% increase in both the adsorption capacities and percent removal was seen in the pH range of 2–6. The second-order kinetic model had a nearly perfect fitting, suggesting that chemisorption was the mechanism controlling adsorption. The Langmuir isotherm model best presented the adsorption data, suggesting that the Pb2+ adsorption was monolayer, and predicted a better affinity between the adsorbent surface and absorbed Pb2+ for MgFe/LDH-Eb_EDTA in comparison to the other two adsorbents. The D–R isotherm suggested that the adsorption system was physical based on E values for all three adsorbents, while the Temkin isotherm model suggested that Pb2+ adsorption was heterogeneous. Finally, the Sips and R–P isotherms predicted that the adsorption of Pb2+ on the surface of the adsorbents was homogeneous and heterogeneous.

Adsorption of Pb Ions from Oily Wastewater by Anthraquinone Modified Carbon Nanotube

The aim of this research was to investigate the adsorption properties of anthraquinone modified carbon nanotube (ACNT) in oily wastewaters containing Pb ions. The modified adsorbents were characterized using Fourier transform infra-red spectroscopy and SEM analysis. The adsorption and regeneration studies were conducted in batch mode using a Taguchi (L16) orthogonal array to optimize experimental runs. The controllable factors used in this study consisted of: pH of the solution (A); adsorbent dosage (B); adsorbent type (C); contact time (D); temperature (F). The effects of each factor were studied at four levels on the removal efficiency of metals from aqueous solution. Concentrations of metal ions were assessed by atomic absorption spectrometer. The total optimum adsorptive removal of lead ions was obtained with C0 = 10 mg•l-1, T = 338 K, pH = 6, m = 0.020 mg and t = 60 min. The Langmuir model was representative to simulate adsorption isotherms. The adsorption kinetics of Pb adsorption by ACNT was modeled using the pseudo-first order, the pseudo-second order, and intraparticle diffusion kinetics equations. The results indicate that the pseudo-second order kinetic equation and intraparticle diffusion model were adequate to describe the adsorption kinetics.

An ecofriendly nanocomposite of bacterial cellulose and hydroxyapatite efficiently removes lead from water

An environmentally friendly nanocomposite adsorbent composed of two renewable biomaterials, bacterial cellulose (BC) nanofibrils and hydroxyapatite (HA) nanocrystals, was synthetized by an in situ wet chemical precipitation technique, using clam shell biowaste as feedstock. HA nanocrystals embedded in an ultrafine BC network were confirmed and characterized trough different instrumental techniques (SEM, FTIR, XRD, EDS, surface charge and BET analysis), describing its nanostructure, chemical composition and thermal stability. The adsorptive removal of lead ions by the nanocomposite was investigated through batch experiments conducted under different pH, contact times and Pb(II) initial concentrations, proving that the process was highly favorable according to the Langmuir isotherm model (monolayer adsorption) with chemisorption as the main mechanism and kinetic data obeying a nonlinear pseudo-second order kinetic model. The developed nanocomposite showed a strong removal capacity of Pb(II) both in batch experiments (192 mg/g) and packed-bed column systems (188 mg/g), placing this new nanocomposite among top-performing BC-based biomaterials for lead removal.

Rapid removal of lead(II) ions from water using iron oxide-tea waste nanocomposite - a kinetic study.

Lead (Pb) ions are a major concern to the environment and human health as they are contemplated cumulative poisons. In this study, facile synthesis of magnetic iron oxide-tea waste nanocomposite is reported for adsorptive removal of lead ions from aqueous solutions and easy magnetic separation of the adsorbent afterwards. The samples were characterised by scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffraction, and Braunner-Emmet-Teller nitrogen adsorption study. Adsorptive removal of Pb(II) ions from aqueous solution was followed by ultraviolet-visible (UV-Vis) spectrophotometry. About 95% Pb(II) ion removal is achieved with the magnetic tea waste within 10 min. A coefficient of regression R2 ≃ 0.99 and adsorption density of 18.83 mg g-1 was found when Pb(II) ions were removed from aqueous solution using magnetic tea waste. The removal of Pb(II) ions follows the pseudo-second-order rate kinetics. External mass transfer principally regulates the rate-limiting phenomena of adsorption of Pb(II) ions on iron oxide-tea waste surface. The results strongly imply that magnetic tea waste has promising potential as an economic and excellent adsorbent for the removal of Pb(II) from water.

The adsorptive removal of lead ions in aquatic media: Performance comparison between advanced functional materials and conventional materials

The low permissible concentration of lead ions (Pb2+) in potable water (15 ppb) makes it even more challenging to develop highly efficient water purification technologies. Adsorption has become one of the preferred water treatment techniques for removing various metal species including Pb2+ ions. However, assessment of adsorbent capacities between the tested materials was often made in a biased manner (e.g., derivation of the maximum capacities under unrealistically high initial feeding conditions). In this work, such comparison was made in terms of partition coefficient (PC) as a key metric for the least biased evaluation to explore the best sorbents among materials with a broad range of breakthrough capacities. Nanoscale sorbents derived from carbon-based nanomaterials and MOFs are highly advantageous, as they can offer highly sensitive and selective adsorption of Pb2+ ions. In general, advanced functional materials showcased better adsorption-desorption efficiency for Pb2+ when compared to conventional materials (e.g., over three regeneration cycles). Continuous research and development for the functional materials are further required to scale down the production cost so that cost-effective technologies may be applied for environmental remediation. The future scope for Pb2+ removal techniques is discussed further with respect to the development of novel functional materials.

Adsorptive Removal of Lead Ions in Aqueous Solution by Kapok-Polyacrylonitrile Nanocomposites

Abstract In this study, the naturally hydrophobic kapok fibers were modified with polyacrylonitrile (PAN) to reverse its wetting property for adsorption of lead (Pb) ions in aqueous solution. Increasing the initial amount of the acrylonitrile (AN) monomer in solution resulted in thicker PAN coating on the surface of the kapok fibers after in situ polymerization. Consequently, the static water contact angle of the nanocomposite was reduced to zero. The kapok-PAN nanocomposites were then used for adsorption of lead (Pb) II in aqueous solution. Adsorption capacities for Pb(II) increased from 22.05 to 26.81 mg/g with higher AN concentration. Hydrolysis of the kapok-PAN nanocomposite was performed by immersing in a sodium hydroxide (NaOH) solution, which results to significantly enhanced adsorption of about 78.34 mg/g.

Novel multifunctional membrane technology for visual detection and enhanced adsorptive removal of lead ions in water and wastewater

A multifunctional membrane for visual detection and enhanced adsorptive removal of lead ions in aqueous solution was prepared by immobilizing lead sensitive ligand, dithizone (DZ), on chitosan (CS) /cellulose acetate (CA) blend membrane. The prepared membrane can display visible color change (from yellow to red) as a response to lead ions in solutions; and at the same time, lead ions can be adsorptively removed by the amine groups on the membrane surface. Thus, the development provides a truly multifunctional membrane technology that can achieve optical warning as well as removal of lead ions simultaneously. Experimental results showed that the prepared membrane exhibited the advantages of quick response, easy naked-eye recognition and improved lead uptake capacity.