To obtain adsorbents with high As(V) removal capacity and quick magnetic separation simultaneously, we have fabricated maghemite (纬-Fe
2O
3) and magnetite (Fe
3O
4) chestnutlike hierarchical nanostructures (CHNs) with strong ferromagnetic property by annealing the Fe
2O
3 chestnutlike amorphous core/纬-phase shell hierarchical nanoarchitectures (CAHNs) at different temperatures in a nitrogen atmosphere. Compared to the Fe
2O
3 CAHNs, the saturated magnetization of the as-obtained 纬-Fe
2O
3 CHNs is enhanced over 10 times, while the As(V) removal capacity is maintained 74% and reaches 101.4 mg路g
鈥?. Both of the as-obtained 纬-Fe
2O
3 and Fe
3O
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 纬-Fe
2O
3 CHNs obeys well the Freundlich isotherm model rather than the Langmuir one, suggesting that a multilayered adsorption occurs on the surface of the 纬-Fe
2O
3 CHNs. Taking advantages of the high adsorption capacity, fast adsorption rate and quick magnetic separation from treated water, the 纬-Fe
2O
3 CHNs developed in the present study is expected to be an efficient magnetic adsorbent for As(V) removal from aqueous solutions.
Keywords:
iron oxide; magnetic properties; hierarchical nanostructures; arsenic adsorption; water treatment