Environmentally Friendly Magnetic Nanoparticles for Efficient Removal of Methylene Blue and Cr(VI) from Water

Abstract

The poor environmental friendliness, low adsorption capacity and nonreusability of adsorbents are still challenging for the removal of pollutants in aqueous solution. Herein, novel polypeptide-functionalized silica-coated magnetic nanoparticles (PS-MNPs), Fe3O4@SiO2@PLL nanoparticles, with good environmental friendliness, excellent adsorption capability and economic reusability were designed and prepared for efficient removal of methylene blue (MB) and Cr(VI) ion (Cr2O[Formula: see text]. The chem-physical properties of Fe3O4@SiO2@PLL nanoparticles, such as chemical structure, nanosize, nanomorphology, crystalline structure, magnetization and thermo-oxidative degradation behavior were fully investigated in this study. In addition, the adsorption properties of the Fe3O4@SiO2@PLL nanoparticles for MB and Cr(VI) ion in aqueous solution were explored by batch adsorption experiments. Based on the experimental results, the Fe3O4@SiO2@PLL nanoparticles demonstrated excellent adsorption capacity for removal of both MB and Cr(VI) ion that the theoretical maximum adsorption capacities of the nanoparticles were 301.2[Formula: see text]mg [Formula: see text] g[Formula: see text] for MB and 164.7[Formula: see text]mg [Formula: see text] g[Formula: see text] for Cr(VI), respectively. The adsorption process could be better fitted by pseudo-second-order model, and matched well with the Langmuir isotherm equation. Moreover, the Fe3O4@SiO2@PLL nanoparticles could be easily regenerated by desorbing metal ions and organic dyes from the adsorbents with appropriate eluents, and showed good adsorption capacity after five recycles. In brief, the as-prepared PS-MNPs exhibited improved environmental friendliness, excellent adsorption properties and high regeneration efficiency, which could be used as a potential adsorbent for different kinds of contaminants removal.

Disulfide Cross-Linked Poly(Methacrylic Acid) Iron Oxide Nanoparticles for Efficiently Selective Adsorption of Pb(II) from Aqueous Solutions

“…Recently, many physicochemical technologies have been used for the treatment of heavy metal ions from polluted water, such as chemical precipitation, ion exchange, membrane filtration, reverse osmosis, and adsorption. , Among these various technologies, the adsorption method is featured by cost-effectiveness, large-scale choice of materials, and ease of operation. Moreover, the adsorbents can be directly dispersed in wastewater to completely contact with pollutants, facilitating an efficient adsorption process. − Although adsorption has been widely applied in the removal of Pb­(II) ions in water treatment, nonselectivity, low adsorption capacity, and nonreusability are still challenging in the application of the conventional adsorbents in the adsorption process for actual wastewater treatment.…”