Characterization and Application Results of Two Magnetic Nanomaterials

Abstract

The toxicity of heavy metals for the environment can be solved by using the adsorption properties of magnetic nanomaterials. These types of nanomaterials can remove pollutants, especially from wastewaters. This study was conducted to determine whether two magnetic nanomaterials can be used as adsorbents for heavy metals (Cr, Cd, Cu, Zn, and Ni) from aqueous solutions under acidic conditions. Qualitative and quantitative elemental information and structural and surface characteristics before and after use as adsorbents were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The obtained data showed a good correlation with the Langmuir adsorption model using the two magnetic nanomaterials in aqueous solutions. The crystalline structure of the FeO powder was identified with XRD. The TEM images of FeO nanoparticles indicated a good dispersion of particles of 85.5 nm. The SEM analysis for FeO-PAA (magnetite covered with sodium alginate) showed spherical particles of magnetite wrapped into the polymer with dimension of ∼200 nm. According to the adsorption Langmuir model, the removal efficiency for uncoated FeO decreased in order: Cr(VI) > Cu(II) > Zn(II) > Ni(II) > Cd(II). For the FeO-PAA nanocomposite (45% w/w Fe in a mass of polymer), the adsorption phenomena appears as follows: Cr(VI) > Cd(II) > Cu(II) ∼ Zn(II) > Ni(II). Langmuir parameters indicated a favorable monolayer adsorption at pH 2.5. The nanocomposite FeO-PAA can be used as an adsorbent with the same performance as uncoated FeO but with the advantage of stability under conditions where industrial wastewaters have an acidic pH.

An Innovative Method of Converting Ferrous Mill Scale Wastes into Superparamagnetic Nanoadsorbents for Water Decontamination

“…Future investigations will be developed. In accordance with other results obtained with the nanostructured iron oxides used for the removal of heavy metals from wastewaters [49,51], the use of MS for ION preparation led to a porous and active nano-adsorbent with promising results for heavy metal removal.…”

Sorptive uptake of selenium with magnetite and its supported materials onto activated carbon

“…Fig. The reduced tendency of leaching can be related to the solvent accessibility due to the surface coverage of magnetite onto AC and its different structural forms [60], in good agreement with PXRD results [12]. The relative stability of the iron oxide materials is supported by the variable leaching observed for the composite materials, as compared with goethite and magnetite.…”

Comparison on depollution capabilities of two iron based magnetic nanopowders

“…0.4 mol/L Fe(NO 3 ) 3 ×9H 2 O and 0.4 mol/L FeCl 2 ×9H 2 O were mixed at a molar ratio of 1:2 in the presence of 0.5 mol/L NaOH in distilled water at room temperature. The pH of the solution was maintained at 10 for 3 h, after which the precipitate was separated by centrifugation and washed several times with distilled water until the pH becomes 7 [6]. In order to prevent agglomeration of the particles, D-sorbitol was added to the solution.…”

“…For the Cr (VI) solution analysis, a Cintra 202 GBC spectrophotometer, with spectral domain between 190 and 1000 nm was used. [6] The removal efficiency was calculated based on the formula [9]:…”

“…The quantity of adsorbents used was 0.1g and the concentrations of metal ions in the synthetic solutions that were tested were selected as 40 and 50 mg/L [6].…”