Magnetic iron oxide chestnutlike hierarchical nanostructures: preparation and their excellent arsenic removal capabilities.
To obtain adsorbents with high As(V) removal capacity and quick magnetic separation simultaneously, we have fabricated maghemite (γ-Fe(2)O(3)) and magnetite (Fe(3)O(4)) chestnutlike hierarchical nanostructures (CHNs) with strong ferromagnetic property by annealing the Fe(2)O(3) chestnutlike amorphous core/γ-phase shell hierarchical nanoarchitectures (CAHNs) at different temperatures in a nitrogen atmosphere. Compared to the Fe(2)O(3) CAHNs, the saturated magnetization of the as-obtained γ-Fe(2)O(3) CHNs is enhanced over 10 times, while the As(V) removal capacity is maintained 74% and reaches 101.4 mg·g(-1). Both of the as-obtained γ-Fe(2)O(3) and Fe(3)O(4) CHNs can be separated simply and rapidly from treated water by magnetic separation after As(V) adsorption treatment. The As(V) adsorption process of the as-obtained γ-Fe(2)O(3) CHNs obeys well the Freundlich isotherm model rather than the Langmuir one, suggesting that a multilayered adsorption occurs on the surface of the γ-Fe(2)O(3) CHNs. Taking advantages of the high adsorption capacity, fast adsorption rate and quick magnetic separation from treated water, the γ-Fe(2)O(3) CHNs developed in the present study is expected to be an efficient magnetic adsorbent for As(V) removal from aqueous solutions.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.
Fangzhi
F
Mou
Jianguo
J
Guan
Huiru
H
Ma
Leilei
L
Xu
Weidong
W
Shi
D000327:Adsorption; D001151:Arsenic / Q000737:chemistry / Q000302:isolation & purification*; D004305:Dose-Response Relationship, Drug; D005290:Ferric Compounds / Q000737:chemistry*; D007700:Kinetics; D008280:Magnetics; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009584:Nitrogen / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods; D013696:Temperature; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods
D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; D014867:Water; C000499:ferric oxide; D001151:Arsenic; D009584:Nitrogen