Continuous preparation of Fe3O4 nanoparticles combined with surface modification by L-cysteine and their application in heavy metal adsorption

L-cysteine functionalized Fe₃O₄ magnetic nanoparticles (Cys–Fe₃O₄ MNPs) were continuously fabricated by a simple high-gravity reactive precipitation method combined with surface modification through a novel impinging stream-rotating packed bed with the assistance of sonication. The obtained Cys–Fe₃O₄ MNPs was characterized by XRD, TEM, FTIR, TGA and VSM, and further used for the removal of heavy metal ions from aqueous solution. The influence of pH values, contact time and initial metal concentration on the adsorption efficiency were investigated. The results revealed that the adsorption of Pb(II) and Cd(II) were pH dependent process, and the pH 6.0 was found to be optimum condition. Moreover, the adsorption kinetic for Cys–Fe₃O₄ MNPs followed the mechanism of the pseudo-second order kinetic model, and their equilibrium data were fitted with the Langmuir isothermal model well. The maximum adsorption capacities calculated from Langmuir equation were 183.5 and 64.35 mg g⁻¹ for Pb(II) and Cd(II) at pH 6.0, respectively. Furthermore, the adsorption and regeneration experiment showed there was about 10% loss in the adsorption capacity of the as-prepared Cys–Fe₃O₄ MNPs for heavy metal ions after 5 times reuse. All the above results provided a potential method for continuously preparing recyclable adsorbent applied in removing toxic metal ions from wastewater through the technology of process intensification.     

Enhanced removal of lead and cadmium from water by Fe3O4-cross linked-O-phenylenediamine nano-composite

A method is presented for surface encapsulation of nano-Fe₃O₄ by o-phenylenediamine via cross-linking using formaldehyde and glutaraldhyde for the formation of two newly designed magnetic nano-sorbents. These have been characterized by FT-IR, TGA, and SEM and maintained the magnetic and thermal stability characters. The metal capacity values of Pb(II) and Cd(II) have been optimized in presence of different physico-chemical parameters and confirmed the superior selectivity for Pb(II). Maximum capacity values of Pb(II) (7000-10000 ± 250-675 µmol g^?1) and Cd(II) (1500-2250 ± 30-75 µmol g^?1) at optimum conditions and excellent extraction values (94.10-100.0 ± 1.2-3.5%) from industrial wastewater have been identified.     

Studies on the synthesis and properties of hydroxyl azacrown ether‐grafted chitosan

The chitosan hydroxyl azacrown ether was synthesized by reaction of hydroxyl azacrown ether with epoxy‐activated chitosan. The C₂ amino group in chitosan was protected from the reaction between benzaldehyde and chitosan to form N‐benzylidene chitosan. After reaction with epichlorohydrin and azacrown ether, reacting O‐aryl mesocyclic diamine‐N‐benzylidene chitosan and dilute ethanol hydrochloride solution to obtain novel chitosan‐azacrown ether bearing hydroxyl removed the Schiff base. Its structure was confirmed with elemental analysis, FTIR spectra analysis, X‐ray diffraction analysis, and solid‐state ¹³C NMR analysis. Its static adsorption properties for Ag(I), Cd(II), Pb(II), and Cr(III) were also investigated. The experimental results showed that the hydroxyl azacrown ether grafted chitosan has good adsorption capacity and high selectivity for Ag(I) in the coexistence of Pb(II) and Cd(II), the selectivity coefficients of hydroxyl azacrown ether chitosan were K_Ag(I)/Pb(II) = 32.34; K_Ag(I)/Cd(II) = 56.12. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1838–1843, 2001     

Adjusted pH for the Selective Separation of Cadmium from Lead by Nano-Active Silica-Functionalized-[Bmim+Tf2 N−] Ionic Liquid

A method is described for the selective separation and extraction of cadmium-lead from aqueous solutions by tuning the pH value between 1.0 and 7.0. A modified nano-active silica sorbent was loaded with 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide hydrophobic ionic liquid, [Bmim⁺Tf₂N^?] and used in this work. The pH value was found to play a significant role in the sorption capacity of Cd(II) and Pb(II). In pH 1.0, the metal capacity values were characterized as 1.40 and 0.30 mmol g^?1 for Cd(II) and Pb(II), respectively. In pH 7.0, Cd(II) and Pb(II) switched their capacity values to 0.65 and 1.00 mmol g^?1, respectively. An anion exchange mechanism was proposed in solution with pH 1.0 for exchange of chloroanionic cadmium species by [Tf₂N^?]. The sorptive separation processes of Cd(II) and Pb(II) were studied and evaluated under the influence of various controlling factors. The potential applications of modified nano-silica sorbent for selective sorptive removal and separation of Cd(II) from Pb(II) in water samples was successfully accomplished by adjusting the pH value of the contact solution between 1.0 and 7.0. The results of this study indicated an efficient extraction behavior of the two examined metal ions.     

Modern hybrid sorbents – New ways of heavy metal removal from waters

The possibility of hybrid ion exchanger (HIX) application in the simultaneous removal of heavy metal ions such as Cr(VI), Cu(II) and Zn(II) as well as Cd(II) and Pb(II) was presented. The ion exchanger in question combines the unique properties of hydrated metal oxides with the mechanical and thermal stability of synthetic ion exchangers. The kinetics of the sorption process of Cr(VI), Cu(II) and Zn(II) as well as Cd(II) and Pb(II) in the presence of Cl⁻, NO₃⁻ and SO₄²⁻ as well as EDDS (ethylenediaminedisuccinic acid) was also analyzed. Additionally, the effect of initial concentration, phase contact time and pH was also studied. Taking into account the possibility of its application on a large scale, the parameters of the adsorption process were estimated based on the linear form of the Langmuir and Freundlich isotherms.     

Magnetic Pb(II) Ion-Imprinted Polymer Prepared by Surface Imprinting Technique and its Adsorption Properties

A novel magnetic Pb(II) ion-imprinted polymer was prepared via surface ion-imprinting technique by using magnetic Fe₃O₄@SiO₂ microspheres as supporter, Pb(II) as template ion, methacrylic acid and salicylaldoxime as monomers, and ethylene glycol dimethacrylate as crosslinker. The product was characterized by FT-IR, VSM, XRD, and SEM. The adsorption experiments showed that the imprinted polymer was employed successfully in comparison with non-imprinted polymer. When the temperature was in a range of 277 K to 291 K the maximum adsorption was about 81.83 mg/g with an optimal pH 6.0. Its relative selectivity coefficient values of Pb(II)/Cu(II), Pb(II)/Zn(II), and Pb(II)/Cd(II) were 2.60, 6.38, and 7.89 times greater than the ones of the magnetic non-imprinted polymer. The Langmuir adsorption model was more favorable for M-IIP than Freundlich or Temkin adsorption models. The Scatchard analysis suggested that M-IIP was processed with two kinds of binding sites with different affinity. Thermodynamic experiment showed that the adsorption was a spontaneous and endothermic process for Pb(II). The mechanism for Pb(II) adsorption on the imprinted polymer was also investigated.     

Kinetic and equilibrium studies of Pb(II) and Cd(II) removal from aqueous solution onto colemanite ore waste

The adsorption characteristics of Pb(II) and Cd(II) onto colemanite ore waste (CW) from aqueous solution were investigated as a function of pH, adsorbent dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the adsorption isotherms. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The adsorption capacity of CW was found to be 33.6 mg/g and 29.7 mg/g for Pb(II) and Cd(II) ions, respectively. Analyte ions were desorbed from CW using both 1 M HCl and 1 M HNO₃. The recovery for both metal ions was found to be higher than 95%. The mean adsorption energies evaluated using the D-R model indicated that the adsorption of Pb(II) and Cd(II) onto CW were taken place by chemisorption. The thermodynamic parameters (ΔG^o, ΔH^o and ΔS^o) showed that the adsorption of both metal ions was feasible, spontaneous and exothermic at 20-50 °C. Adsorption mechanisms were also investigated using the pseudo-first-order and pseudo-second-order kinetic models. The kinetic results showed that the adsorption of Pb(II) and Cd(II) onto CW followed well pseudo-second order kinetics.     

Simultaneous preconcentration of Cd(II), Cu(II) and Pb(II) on Nano-TiO2 modified with 2-mercaptobenzothiazole prior to flame atomic absorption spectrometric determination

Nano-TiO₂ modified with 2-mercaptobenzothiazole (MBT) was investigated as a new adsorbent for preconcentration of Cd(II), Cu(II) and Pb(II). The metal ions are adsorbed onto nano-TiO₂-MBT, eluted by nitric acid and determined by flame atomic absorption spectrometry. The parameters affecting the adsorption were investigated. Under optimized conditions, the calibration curves were linear in the range of 0.2–25.0, 0.2–20.0, and 3.0–70.0 ng mL⁻¹ for cadmium, copper and lead, respectively. The limits of detection for Cd(II), Cu(II) and Pb(II) were 0.12, 0.15 and 1.38 ng mL⁻¹, respectively. The method was applied to determination of Cd(II), Cu(II) and Pb(II) in water and ore samples.     

Preparation and Characterization of Poly(2,2-dimethyl-1,3-propylene oxalate) Polymer and the Study of its Metal Uptake Behavior Toward Pb(II), Cd(II), and Hg(II) Ions

Abstract

Poly(2,2-dimethyl-1,3-propylene oxalate) was synthesized from oxalyl chloride and 2,2-dimethyl-1,3-propane diol. The polymer was characterized by inherent viscosity, FT-IR, XRD, SEM, ¹H-NMR, ¹³C-NMR, DSC, and TGA. The polymer uptake behavior towards Pb(II), Cd(II), and Hg(II) ions was studied by the batch equilibrium technique as a function of pH and contact time. The adsorption isotherms of metal ions were also investigated. Column experiments were used to determine the loading capacity and study desorption of metal ions. The polymer showed high metal-ion uptake capacity towards Pb(II), but moderate capacity towards Cd(II) and Hg(II) ions. Interestingly, the polymer was found to be highly selective for Pb(II) ions at pH 5 and 25°C. The metal ion uptake properties of the polymer show fittings for both Langmuir's and Freundlich equations. The metal-bound polymer was regenerated by treatment with 1 M HNO₃. Therefore, it may be employed for the removal of heavy metal pollutants in environmental and industrial applications.     

Synthesis of new chelating ion exchange resin with hydroxamic and amidoxime groups and study of its metal binding property

The synthesis of a new chelating ion exchanger with hydroxamic and amidoxime groups was performed by an aminolysis reaction of an ethylacrylate/acrylonitrile/divinylbenzene copolymer with hydroxylamine in the presence of sodium ethoxylate. We studied the retention property of the new resin for Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Mn(II), and Fe(III) metal cations from aqueous solutions. The retention capacity depends on the contact time, the pH of the solution, and the types of counterions of the metal cations. Competitive adsorptions of Pb(NO₃)₂ + Fe₂(SO₄)₃, Pb(NO₃)₂ + MnSO₄, Pb(NO₃)₂ + Cd(NO₃)₂, and Pb(NO₃)₂ + CuCl₂ on the new chelating ion exchanger were performed. The results showed that the resin preferentially retained the Pb(II) ions from the binary aqueous mixtures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2956–2962, 2003     

Valine-Coated Magnetic Nanoparticles: Synthesis,Characterization, and Application in Removal of Cd(II) Ions from Aqueous Solution

A novel Valine coated magnetic nano-particles (MNPs-Val) has been synthesized for the removal of Cd(II) ions from aqueous solution. The MNPs-Val were developed by electrostatic attraction of valine (C₅H₁₁NO₂) on the bare surface of Fe₃O₄ nanoparticles and characterized by using FT-IR, XRD, SEM, and TEM analysis. The morphology and average particles size 15-27 nm of MNPs-Val were analyzed by SEM and TEM. The coated MNPs were applied for adsorptive removal of Cd(II) ions from aqueous solutions. Factors affecting the adsorption of Cd(II) ions on the MNPs-Val surface such as the pH, temperature, adsorbent dosage, and contact time were investigated which have significant effect on the metal ion removal. The Cd(II) ions adsorption equilibrium on the MNPs-Val could be achieved in 35 min at the optimized pH 5 and follow the pseudo-second order kinetics model. The experimental data for the adsorption of Cd(II) was followed by the Langmuir isotherm and the maximum adsorption capacity was obtained at 0.2 g L^?1 adsorbent dose at 308 K.     

Synthesis,characterization, and application of a new chelating resin functionalized with dithiooxamide

Chloromethylated polystyrene‐divinylbenzene has been functionalized with dithiooxamide. The resulting chelating resin (DTOA) has been characterized by elemental analyses, infrared spectroscopy, thermogravimetric analysis, and metal ion sorption capacities. It has been used for the preconcentration and separation of Cu(II), Zn(II), Cd(II), and Pb(II) prior to their determination by FAAS. Parameters such as the amount of the resin, effect of pH, equilibration rate, sorption and desorption of metal ions, and effect of diverse ions have been studied. The maximum sorption capacities found are 0.97, 0.12, 0.08, and 0.12 mmol g^?1 for Cu(II), Zn(II), Cd(II), and Pb(II) at pH 6.0, 5.5, 1.0, and 5.5, respectively. The preconcentration factors are 100, 100, 50, and 50 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. Recoveries of the metal ions were 96 ± 5, 97 ± 6, 96 ± 5, and 96 ± 5 at 95% confidence level, whereas the limits of detection are 2.0, 1.3, 2.5, and 25.0 μg L^?1 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The calibration curves were linear up to 12 μg mL^?1 (R² = 1.000), 2 μg mL^?1 (R² = 0.998), 2 μg ml^?1 (R² = 1.000), and 5 μg mL^?1 (R² = 0.979) for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The reliability of the method has been tested by analyzing certified samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2281–2285, 2007     

Synergistic Effect of Maghemite and Titania Nanoparticles in PVA-Alginate Encapsulated Beads for Photocatalytic Reduction of Pb(II)

In this paper, maghemite (γ-Fe₂O₃) and titanium oxide (TiO₂) nanoparticles were synthesized by hydrothermal and coprecipitation methods, respectively. These nanoparticles were combined together in various ratios (1:10, 1:20, 1:60, 1:80, and 1) and embedded in polyvinyl alcohol (PVA)-alginate beads. These beads were tested for photocatalytic behavior in eliminating toxic Pb(II) from the aqueous solution. The photocatalytic experiments were performed under sunlight irradiation and without sunlight. Several operating conditions such as initial Pb(II) concentration, pH, contact time, and TiO₂: γ-Fe₂O₃ ratios were investigated to evaluate their effect on the process. The recycling attributes of these beads were also investigated. The results revealed that 100% of the Pb(II) was eliminated in 100 min at pH 7 under sunlight when the ratio of TiO₂:γ-Fe₂O₃ was kept to 1. The PVA-alginate maghemite and titania beads showed better efficiency for Pb(II) removal than PVA-alginate titania beads and PVA-alginate maghemite beads. X-ray photoelectron spectroscopy (XPS) analysis also revealed that Pb(II) removal was via photocatalytic reduction due to the presence of Pb(0) in the high-resolution scan at 130–160 eV. Also, the PVA-alginate titania and maghemite beads can be readily isolated from the aqueous solution after the photocatalytic process and reused for at least 6 times without significant losses in their initial properties. The reduction of Pb(II) with PVA-alginate titania and maghemite beads fitted the Langmuir–Hinshelwood (L–H) kinetic model at a correlation coefficient (R²) of 0.9923.     

Electrochemical synthesis of ammonia from water and nitrogen catalyzed by nano-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> and CoFe<Subscript>2</Subscript>O<Subscript>4</Subscript> suspended in a molten LiCl-KCl-CsCl electrolyte

Nano-Fe₂O₃ and CoFe₂O₄ were suspended in molten salt of alkali-metal chloride (LiCl-KCl-CsCl) and their catalytic activity in electrochemical ammonia synthesis was evaluated from potentiostatic electrolysis at 600 K. The presence of nanoparticle suspension in the molten chloride resulted in improved production of NH₃, recording NH₃ synthesis rate of 1.78×10^?10 mol s^?1 cm^?2 and 3.00×10^?10 mol s^?1 cm^?2 with CoFe₂O₄ and Fe₂O₃, which are 102% and 240% higher than that without the use of a nanocatalyst, respectively. We speculated that the nanoparticles triggered both the electrochemical reduction of nitrogen and also chemical reaction between nitrogen and hydrogen that was produced from water electro-reduction on cathode. The use of nanocatalysts in the form of suspension offers an effective way to overcome the sluggish nature of nitrogen reduction in the molten chloride electrolyte.     

Synthesis of AgBiS2/gC3N4 and its application in the photocatalytic reduction of Pb(II) in the matrix of methyl orange,crystal violet,and methylene blue dyes

The removal of lead ions in contaminated water by the reduction of Pb(II) ions to the useful metallic Pb is challenging, especially in water polluted by other contaminants such as dye molecules. Most investigations focussed on the removal of Pb(II) in a single system. In reality, contaminated water contains a mixture of organic pollutants and heavy metals. Herein, we synthesized graphitic carbon nitride functionalized with ternary silver bismuth sulphide (AgBiS₂/gC₃N₄) for the photocatalytic removal of Pb(II) from dye-containing water. The as-synthesized gC₃N₄, AgBiS₂, and AgBiS₂/gC₃N₄ composite were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). The composite was used for the photocatalytic reduction of Pb(II) in the matrix of methyl orange, crystal violet, and methylene blue. The effect of the presence of easily-oxidizable organics and persulphate on the photocatalytic reduction of Pb(II) was also investigated. The results revealed that the presence of easily-oxidizable organics has synergistic effects on the photocatalytic reduction of Pb(II), while persulphate displayed inhibitive effect on Pb(II) reduction. The removal of Pb(II) in the dyes matrix was influenced by the type of dyes that were present in the water. The rate of Pb(II) reduction was reduced in the presence of methylene blue and methyl orange, but crystal violet displayed synergistic effects. Finally, the rate of degradation of dyes in the presence of Pb(II) was investigated. The rate of photocatalytic reduction of Pb(II) decreased from 0.0045 min^?1 to 0.0036 min^?1 and 0.0016 min^?1 in the matrix of methyl orange and methylene blue respectively. On the contrary, there was an increase in the rate of photocatalytic reduction of Pb(II) from 0.0045 to 0.0096 min^?1 in the matrix of crystal violet.     

The activity of Rh/Al2O3 and Rh-Na/Al2O3 catalysts for PAHs removal in the waste incineration processes: Effects of particulates, heavy metals, and acid gases

This study investigated the activity of Rh/Al₂O₃ and Rh-Na/Al₂O₃ catalysts for polycyclic aromatic hydrocarbons (PAHs) removal and the influence of particulates, heavy metals, and acid gases (SO₂ and HCl) on the performance of catalysts. The experiments were carried out in a laboratory-scale waste incineration system. Experimental results show that the destruction removal efficiency (DRE) of PAHs by Rh/Al₂O₃ and Rh-Na/Al₂O₃ catalysts were 80% and 59%, respectively when the flue gas did not contain any pollutants. The concentrations of PAHs increased by using a Rh/Al₂O₃ catalyst when the flue gas contained Cd, Pb, and SO₂ and also increased by using a Rh-Na/Al₂O₃ catalyst when the flue gas contained particulates, Cd, and HCl. Adding Na to the Rh/Al₂O₃ catalyst can inhibit the increases of 3-4 ring PAHs when the flue gas contained Pb. The influence of acid gases on the performance of the Rh/Al₂O₃ and Rh-Na/Al₂O₃ catalysts followed the sequence SO₂ > HCl > SO₂ + HCl. The activity of the catalysts for PAHs removal was significantly suppressed by increased concentrations in particulates and Cd, yet promoted by a high Pb concentration. The results of ESCA analysis indicated that the presence of Cd and Pb did not change the chemical states of Rh and Na, but the presence of SO₂ and HCl did.     

Removal of Pb(ii) ions from aqueous solution using a novel composite adsorbent of Fe3o4/PVA/spent coffee grounds

ABSTRACT

A novel magnetic composite prepared from Fe₃O₄, poly(vinyl alcohol) and alkaline pretreated spent coffee grounds (Fe₃O₄/PVA/APSCGs) was utilized for the first time as an adsorbent for adsorption of Pb(II) ions after carefully characterizing it by various techniques (XRD, FTIR, SEM, EDX). The obtained results indicated that the adsorption was spontaneous, endothermic, fitting well with both Langmuir and Freundlich models, and more suitable to be described by the second-order kinetic model. The maximum adsorption capacity of Fe₃O₄/PVA/APSCGs for Pb(II) at optimum conditions (pH of 5, contact time of 24 h, APSCGs:Fe₃O₄ weight ratio of 4:1) was found to be 0.275 mmol.g^?1. Recycling study showed a good reusability of the composite with removal efficiency maintained at 78.12% after five continuous adsorption-desorption cycles.     

Preparation of amidoximated polyester fiber and competitive adsorption of some heavy metal ions from aqueous solution onto this fiber

In this study, a fibrous adsorbent containing amidoxime groups was prepared by graft copolymerization of acrylonitrile (AN) onto poly(ethylene terephthalate) (PET) fibers using benzoyl peroxide (Bz₂O₂) as initiator in aqueous solution, and subsequent chemical modification of cyano groups by reaction with hydroxylamine hydrochloride in methanol. The grafted and modified fibers were characterized by FTIR, TGA, SEM, and XRD analysis. The crystallinity increased, but thermal stability decreased with grafting and amidoximation. The removal of Cu(II), Ni(II), Co(II), Pb(II), and Cd(II) ions from aqueous solution onto chelating fibers were studied using batch adsorption method. These properties were investigated under competitive conditions. The effects of the pH, contact time, and initial ion concentration on the removal percentage of ions were studied. The results show that the adsorption rate of metal ions followed the given order Co(II) > Pb(II) > Cd(II) > Ni(II) > Cu(II). The percentage removal of ions increased with initial ion concentration, shaking time, and pH of the medium. Total metal ion removal capacity was 49.75 mg/g fiber on amidoximated fiber. It was observed that amidoximated fibers can be regenerated by acid without losing their activity, and it is more selective for Pb(II) ions in the mixed solution of Pb‐Cu‐Ni–Co‐Cd at pH 4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

1,5-Bis(2,5-Difluorophenyl)-3-Mercaptoformazan. A New Tetrafluorinated Dithizone Analogue

Abstract

1,5-Bis(2,5-difluorophenyl)-3-mercaptoformazan (2,2′, 5.5′-tetrafluorodithizone, F₄ H₄ Dz) has been synthesized; its electronic spectra was found to be significantly different from that of dithizone. Its pH_½ in chloroform (8.4) and in carbon tetra-chloride (7.4) are lower than the corresponding values (10.6 and 8.8, respectively) for dithizone. The partition coefficient of the reagent is remarkably decreased in chloroform (270) and in carbon tetrachloride (160) due to the presence of fluorine atoms, compared to the corresponding values (10⁴.89 and 10⁴.18, respectively) for dithizone. The extraction constants of its complexes with Cd(II), Cu(II), Pb(II), Co(II), Hg(II), and Zn(II) were found to be higher than the corresponding values of dithizone complexes, thus enabling their extraction from more acidic solutions. The new reagent seems also to be slightly more sensitive for Bi(III), Cd(II), Co(II), Cu(II), and Hg(II).     

Environmental water remediation using covalently functionalized zerovalent iron nanocomposites with 2-pyridinecarboxaldehyde via 3-aminopropyltrimethoxysilane and ethylenediamine

The adsorption technology involving nano zerovalent iron (NZVI) has been widely employed to remediate polluted water based on a number of economic aspects. However, this technology is facing a high challenge in the removal process of pollutants due to hydrolysis and stability characteristics of zerovalent iron. Therefore, this study is aimed to demonstrate a method for encapsulation and functionalization of NZVI nanoparticles with 3-aminopropyltrimethoxysilane (NH₂) and 2-pyridinecarboxaldehyde (PY), respectively to produce the target nanocomposite (NZVI-NH₂-PY). Zerovalent iron nanoparticles are also aimed to functionalize with ethylenediamine (ED) and 2-pyridine carboxaldehyde to produce NZVI-ED-PY nanocomposite. The TEM images showed that the sizes of NZVI-NH₂-PY and NZVI-ED-PY nanocomposites are in the range 3.33–4.35 and 5.42–10.36 nm, respectively. More characterization evidences were concluded by thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The two novel magnetic nanocomposites have been used for removal of Co(II), Zn(II), Pb(II), Cd(II), Hg(II), Cu(II) beside radioactive isotopes (⁶⁵Zn and ⁶⁰Co) from water. NZVI-NH₂-PY nanocomposite was more selective toward Hg(II), Pb(II) and Cd(II), while NZVI-ED-PY was more selective toward Z(II), Co(II) and Co(II). Different kinetic models were applied and the investigated metal ions were characterized to undergo the pseudo-second order using both NZVI-NH₂-PY and NZVI-ED-PY nanocomposites.