Preparation of nanocomposites for the removal of phenolic compounds from aqueous solutions

Alginate beads, with and without different types of organo-modified clays, were obtained using a calcium chloride (CaCl2) solution. Firstly, raw clays were organo-modified with a cationic surfactant, hexadecyl trimethylammonium (HDTMA). Then, their cationic exchange capacities (CEC) were calculated and they also were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Afterwards, the obtained polymers and clay polymer nanocomposites (CPN) were carefully characterized by means of the same techniques. Later, different phenol and 4-chlorophenol (4CF) aqueous solutions were prepared and put in contact, for different periods of time, with the synthesized CPN. Phenol and 4CF concentrations were measured by means of UV-vis spectroscopy. Results indicated a successful modification of the raw clay with this cationic surfactant and its incorporation into the alginate polymer matrix. Finally, the maximum removal capacities for both phenolic compounds, 4CF and phenol, were found at qe = 0.334 mg.g(-1) and qe = 0.118 mg.g(-1), respectively.