Fe3O4 (Fe3O4-CS) coated with magnetic chitosan was prepared as an adsorbent for the removal of Orange I from aqueous solutions and characterized by FTIR, XRD, SEM, TEM and TGA measurements. The effects of pH, initial concentration and contact time on the adsorption of Orange I from aqueous solutions were investigated. The decoloration rate was higher than 94% in the initial concentration range of 50–150 mg L−1 at pH 2.0. The maximum adsorption amount was 183.2 mg g−1 and was obtained at an initial concentration of 400 mg L−1 at pH 2.0. The adsorption equilibrium was reached in 30 minutes, demonstrating that the obtained adsorbent has the potential for practical application. The equilibrium adsorption isotherm was analyzed by the Freundlich and Langmuir models, and the adsorption kinetics were analyzed by the pseudo-first-order and pseudo-second-order kinetic models. The higher linear correlation coefficients showed that the Langmuir model (R2 = 0.9995) and pseudo-second-order model (R2 = 0.9561) offered the better fits.

Novel adsorbent, montmorillonite supported porous carbon nanospheres (MMT-PCN) were conveniently synthesized by a hydrothermal carbonization and chemical activation treatment with ZnCl2.

In this research, chitosan coated Fe 3 O 4 as a new adsorbent for the removal of furfural from aqueous solutions was successfully synthesized. The adsorbent was characterized by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). These results indicate that the Fe 3 O 4 is coated with chitosan successfully. In order to find the optimum adsorption conditions, a series of batch adsorption experiments were performed. As a result, the maximum adsorption capability (121.7 mg g À1 ) was obtained at pH ¼ 8, rotational speed ¼ 200 rpm, contact time ¼ 5 h. Moreover, the adsorption kinetics of furfural by adsorbent were examined and the kinetic data indicates that the adsorption process could be well described by the Freundlich isotherm model.

A new adsorbent, sodium polyacrylate (PAANa) grafted onto the surface of bentonite (Bent), was successfully synthesized by a facile and green Ce(iv)-redox process, to remove Pb2+ from aqueous solutions.

The main object of this work is to remove Amido black 10B using a new type of bentonite-based adsorbent with cationic groups by the modification of polyallyl amines between the interlayers of bentonite. Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy were used to characterize the functionalized bentonite. A series of batch adsorption experiments were performed. The maximum adsorption amount was 144.08 mg g−1 when the pH was 2 and the contact time was 120 min. In addition, the equilibrium isotherm data were analyzed using Langmuir and Freundlich isotherm models, while only the Langmuir model could provide a high correlation. Therefore, this study provided a new functionalized bentonite as a low-cost adsorbent for dye removal from water.