Synthesis and characterization of magnetic activated carbon developed from palm kernel shells

Abstract

Magnetic activated carbon (MG-AC), a solid product made by dispersing magnetic substrates on AC, is gaining attention for the removal of heavy metals from wastewater due to its favorable physico-chemical properties such as enhanced surface area and magnetic properties, respectively. However, the effects of two contrasting substrates, i.e., metal solution and metal particles, for the synthesis of MG-AC to obtain enhanced magnetic property have not been considered. The MG-AC was prepared by incorporating Fe3O4 into the AC from two different sources of iron: Fe3O4 extracted from electric arc furnace slag and from a ferric chloride/ferrous sulfate solution, to produce magnetic palm kernel shell from slag (MG-PKSS) and magnetic palm kernel shell from iron suspension (MG-PKSF), respectively. The adsorbent samples were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, X-ray diffraction, electron microscopy, i.e., SEM and FESEM, energy-dispersive X-ray, nitrogen adsorption, vibrating sample magnetometer. The results showed that the MG-PKSF had a greater BET surface area of 257 m2 g−1, a pore volume of 0.1124 cc g−1 and higher magnetic properties with a magnetic saturation of 49.55 emu g−1 relative to the MG-PKSS. The FTIR spectrum of the MG-PKSF illustrated the intense OH bending at 1629 cm−1 which can be attributed to the presence of oxygen in the samples. The absorption bands at 1093 and 579 cm−1 indicated the presence of C–O stretching and metal–oxygen (M–O) bands due to the interaction of iron and oxygen. Therefore, the MG-PKSF presented better characteristics for heavy metal removal from wastewater relative to the MG-PKSS, thereby suggesting that the raw material (metal solution) for impregnation played a crucial role in enhancing the quality of the MG-AC.