An adsorption–reduction synergistic effect of mesoporous Fe/SiO2–NH2 hollow spheres for the removal of Cr(vi) ions

Mesoporous Fe/SiO2–NH2 hollow spheres were successfully prepared as a magnetic absorbent for the highly effective removal of Cr(vi) ions through an adsorption–reduction synergistic effect.

PREPARATION OF MAGNETIC OXIDIZED MULTI-WALLED CARBON NANOTUBES FOR THE ADSORPTION OF RHODAMINE B IN AQUEOUS SOLUTION

A facile and effective approach based on magnetic separation was developed for the adsorption of Rhodamine B ( RhB ) from aqueous solution using magnetic oxidized multi-walled carbon nanotubes (magnetic o-MWCNTs) as adsorbent. The magnetic o-MWCNTs were simply synthesized by assembling magnetic nanoparticles onto the oxidized MWCNTs. Adsorption conditions such as pH values, the dosage of adsorbent added and adsorption time were investigated and optimized to achieve the best removal value. In addition, kinetics, adsorption isotherms and adsorption thermodynamics were studied to understand the mechanism by which the magnetic o-MWCNTs adsorbed RhB . The results indicated that the proposed method based on magnetic o-MWCNTs as magnetic absorbent was rapid and efficient for the removal of RhB . Furthermore, the magnetic o-MWCNTs could be easily removed after adsorption process and regenerated through desorption by ethanol.

Sepiolite/CuFe2O4 Composite: a Magnetic Absorbent for Removal of Contaminants from Water

The sepiolite and CuFe2O4were combined to prepare the sepiolite/CuFe2O4composite. The magnetic composite was characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM) and vibration sample magnetometer (VSM) and N2adsorption isotherms. Adsorption characteristics of the composite were examined by using Cu2+and methylene blue as adsorbates. The results show that CuFe2O4particles adhere to the surface of sepiolite fiber to form the sepiolite/CuFe2O4composite which show well characteristic of superparamagnetism and is effective for the removal of Cu2+or methylene blue. When the mass ratios of sepiolite and CuFe2O4is 7:3, the saturation and remanence magnetization are 7.140 and 0.0246 A·m2/kg, and coercive force is 0.0180 A/m for magnetic sepiolite. The saturated adsorption capacity for Cu2+and the removal rate of methylene blue is 15.72 mg/g, 99.48%, respectively.