Development of a low-cost adsorbent obtained from moringa oleifera and functionalized with iron nanoparticles for removal of oil from produced water

Abstract

An activated carbon was developed from Moringa oleifera seed and modified with iron nanoparticles (AC-Fe) for application in the oils and greases (O&G) adsorption of the produced water. Activated carbon was prepared by pyrolysis and chemical activation using NaOH. Surface modification was performed by the wet impregnation method. AC-Fe was characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area analyzer (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Boehm titration, and point of zero charge (pHPZC). The amount of O&G adsorbed on AC-Fe was sensitive to pH, initial concentration and temperature, but independent of ionic strength. Freundlich isotherm adjusted well, confirming the heterogeneous distribution of active sites and multilayer. The pseudo-second-order kinetic model accurately represents the O&G adsorption process by AC-Fe. Under different temperatures, the maximum amount of O&G adsorption in AC-Fe calculated by the pseudo-second-order kinetic model was 121.95 mg g-1 (298 K), 111.11 mg g-1 (303 K), and 106.38 mg g-1 (308 K). This high adsorption capacity demonstrates the new material potential as a low-cost adsorbent for O&G removal.