Walnut shell supported nanoscale Fe⁰ for the removal of Cu(II) and Ni(II) ions from water

Abstract

The walnut shell supported nanoscale zero‐valent iron (walnut‐nZVI) was prepared from sodium borohydride, iron(II) chloride tetrahydrate, and walnut shell by liquid phase chemical reduction and characterized by FTIR, TEM, and XRD. The composites were tested as adsorbent for the removal of Cu(II) or Ni(II) ions. The equilibrium data were analyzed by the Langmuir, Freundlich, Dubinin–Radushkevich, which revealed that Langmuir isotherm was more suitable for describing Cu(II) and Ni(II) ions adsorption than the other two isotherm models. The results indicated that the maximum adsorption capacity was higher than some other modified biomass waste adsorbents under the proposed conditions, were 458.7, 327.9 mg g−1 for Cu(II) or Ni(II). The adsorption kinetics data indicated that the adsorption fitted well with the pseudo‐second‐order kinetic model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43304.

Pb(II) Removal from Aqueous Solutions by Adsorption on Stabilized Zero-Valent Iron Nanoparticles—A Green Approach

“…As a means of overcoming these disadvantages, the idea of immobilizing the ZVFe NPs into porous host materials was proposed and discussed in several research studies. Three main categories of porous host materials are available for the stabilization of iron NPs: (i) natural minerals, namely pillared clay [18], pumice granular [19,20], acid activated sepiolites [21,22], montmorillonite [23,24], kaolin [25], bentonite [26,27], zeolite [28][29][30], biochar [31,32], and charcoal [33]; (ii) biomaterials such as pine cone [34], aquatic plant Azolla filiculoides [35], cellulose nanofibrils [36], walnut shell [37], and macroporous alginate ( [38,39]); and (iii) synthetic materials such as cationic resin [40], anion exchange resin [41], porous carbon sheet [42], chelating resin [43], titanate nanotube [44], meso-porous silica carbon [45], layered double hydroxide [46,47], activated carbon [34,48,49], graphene oxide [45,50], chitosan [51], carbon nanotube [52], magnesium (hydr)oxide [19,53], and humic acid [54].…”

The sorption of metal ions on nanoscale zero-valent iron

“…The values of qmaxL and KL, in the Langmuir model, and Kf and 1/nf, in the Freundlich model, were, in the study of Yang et al [12], 398.4 mg/g, 0.029dm 3 /mg and 199.8 (mg/g)(dm 3 /mg) 1/n , 0.084, at ca. 20 o C. These values are of similar magnitude as was obtained with the use of GT-nZVI.…”

“…Yang et al [12] studied also the sorption of copper on adsorbent. This was the walnut shell supported nanoscale zero-valent iron.…”

Efficient NiO Impregnated Walnut Shell-Derived Carbon for Dye-Sensitized Solar Cells

“…The asymmetric and symmetric stretching vibrations of C–H bonds (ν-C–H) are represented by the tiny band at 2935 cm –1 . Carbonyl groups (ν-CO) have a strong band at 1740 cm –1 , while CC bonds (ν-CC) have a strong band at 1620 cm –1 . Asymmetric stretching of COO– groups could be attributed to the following tiny band at 1370 cm –1 .…”

“…Carbonyl groups (ν-CO) have a strong band at 1740 cm −1 , while CC bonds (ν-CC) have a strong band at 1620 cm −1 . 37 Asymmetric stretching of COO− groups could be attributed to the following tiny band at 1370 cm −1 . The peak at 1260 cm −1 relates to the deformation vibration of CO and stretching formation of the O−H of carboxylic acids and phenols, whereas the C−O band in the −OCH 3 groups of lignin corresponds to the peak at 1060 cm −1 .…”