Preparation of Magnetic Composite Polyaniline/Fe3O4−Hydrotalcite and Performance in Removal of Methyl Orange

Magnetic composite fabricated from polyaniline and Fe3O4-hydrotalcite (Pan/MHT) was successfully applicated for removal of methyl orange (MO) from wastewater. The structure and properties of Pan/MHT were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, and BrunauerEmmett-Teller adsorption isotherm. Adsorption kinetic results indicated that the adsorption process followed pseudosecondorder kinetic model (R2 = 0:999), MO adsorption onto Pan/MHT was well described by Freundlich isotherm (R2 = 0:994), and the MO adsorption capacity of 2 Pan/MHT obtained the highest with Qe = 156:25 mg/g. Batch adsorption experiments were carried out using magnetic composite with the effects of initial MO concentration, solution pH, and adsorbent dosage. The results revealed that the magnetic Pan/MHT exhibited efficient adsorption of MO in the aqueous solution as a result of the affinity for organic dyes, microporous structure, and suitable surface area for adsorption (15,460 m2 /g). The superparamagnetic behavior of Pan/MHT (withHc = 18:56 Oe, Ms = 23:38 × 10−3 emu/g, andMr = 0:91 × 10−3 emu/g) helps that it could be separated from the solution and performs as an economical and alternative adsorbent to removal and degrade azo dye from wastewater. Pan/MHT was also investigated to reuse after desorption of MO in 0.1 M HCl, and the results show that 2 Pan/ MHT can be reused for 4 cycles with Qe = 79:66 mg/g: