Coating Fe3O4 magnetic nanoparticles with humic acid for high efficient removal of heavy metals in water.

By Jing-fu Liu, Zong-shan Zhao, G. Jiang. Environmental Science and Technology, 2008

1,006 citations recorded by the source corpus.

Humic acid (HA) coated Fe3O4 nanoparticles (Fe3O4/HA) were developed for the removal of toxic Hg(II), Pb(II), Cd(II), and Cu(II) from water. Fe3O4/HA were prepared by a coprecipitation procedure with cheap and environmentally friendly iron salts and HA. TOC and XPS analysis showed the as-prepared Fe3O4/HA contains approximately 11% (w/w) of HA which are fractions abundant in O and N-based functional groups. TEM images and laser particle size analysis revealed the Fe3O4/HA (with approximately 10 nm Fe3O4 cores) aggregated in aqueous suspensions to form aggregates with an average hydrodynamic size of approximately 140 nm. With a saturation magnetization of 79.6 emu/g, the Fe3O4/HA can be simply recovered from water with magnetic separations at low magnetic field gradients within a few minutes. Sorption of the heavy metals to Fe3O4/HA reached equilibrium in less than 15 min, and agreed well to the Langmuir adsorption model with maximum adsorption capacities from 46.3 to 97.7 mg/g. The Fe3O4/HA was stable in tap water, natural waters, and acidic/ basic solutions ranging from 0.1 M HCl to 2 M NaOH with low leaching of Fe (< or = 3.7%) and HA (< or = 5.3%). The Fe3O4/HA was able to remove over 99% of Hg(ll) and Pb(ll) and over 95% of Cu(II) and Cd(II) in natural and tap water at optimized pH. Leaching back of the Fe3O4/HA sorbed heavy metals in water was found to be negligible.

Subfields: Biomedical Engineering, Geochemistry and Petrology, Water Science and Technology

View Paper: https://www.semanticscholar.org/paper/6c73fc059ed939883caee3f87def39f4142bb432

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Citations in the corpus

Nanoparticles as Adsorbent; A Positive Approach for Removal of Noxious Metal Ions: A Review (2015, background): “…oxide and carbon based nanocomposite/hybrid materials have been developed for water purification; these are composed of two or more components and can exhibit the properties of multi component systems in the same material (Liu et al., 2008; Lefevre et al., 2008; Shen et al., 2009; Hu et al., 2005).”
PEI-grafted magnetic porous powder for highly effective adsorption of heavy metal ions (2011, background): “As it was reported that humic acid coated Fe3O4 nanoparticles lost its magnetism completely under 5 mol/L HCl [33], and the dissolution of Fe content on amino-functionalized Fe3O4@SiO2 nanomaterial and magnetic zeolites were 100% in 1 mol/L HCl [11,34].”
Preparation and application of stability enhanced magnetic nanoparticles for rapid removal of Cr(VI) (2011, background): “For instance, Fe3O4 nanoparticle coated with humic acid was found to be an effective adsorbent for Hg, Pb, Cd, and Cu from wastewater [6].”
Impact of humic/fulvic acid on the removal of heavy metals from aqueous solutions using nanomaterials: a review. (2014, background): “Other studies found that the removal of Cr (VI) by ZVI in the presence of HA/FA was nearly unaffected over the pH range of 6.0–9.5 (Mak and Lo, 2011; Liu et al., 2008c, 2009a, 2009b; Dries et al., 2005).”
Functional Oxide Nanomaterials and Nanocomposites for the Removal of Heavy Metals and Dyes (2013, background): “1 mg L-1 10 mg, pH 6, 15 min 99 (Hg2+, Pb2+), 95 (Cu2+, Cd2+) [29]”