Production of adsorbent from activated carbon of palm oil shells coated by Fe3O4 particle to remove crystal violet in water

Abstract

This study focused on making environmentally friendly activated carbon (AC) derived from palm oil shells producing a palm-based powdered activated carbon (PPAC) coated with Fe3O4 particles (PPAC-Fe3O4) as an adsorbent to adsorb crystal violet (CV) dyes in water. Activation of carbon from oil palm shells was carried out chemically using a H3PO4 solution of 10%. The characterization results of PPAC-Fe3O4 adsorbent using X-ray diffraction, nitrogen adsorption–desorption isotherms, and scanning electron microscopy-energy dispersive-X ray (SEM-EDX) compared with PPAC show that the coating process of Fe3O4 particle on PPAC has been carried out successfully to produce the adsorbent of PPAC-Fe3O4. Adsorption of CV dyes on PPAC and PPAC-Fe3O4 was optimum at pH 10 with an adsorbent dose of 2.5 g L–1, and contact time of 90 min. The CV dye adsorption kinetics model on PPAC and PPAC-Fe3O4 tends to follow the pseudo-second-order kinetic model with the rate constants (k2) for PPAC and PPAC-Fe3O4 of 0.059 and 0.088 g mg–1 min–1, respectively. In addition, the adsorption isotherm model of CV dyes on PPAC and PPAC-Fe3O4 tends to follow the Freundlich adsorption isotherm with KF values of 1.066 and 2.852 (mg g–1) (L mg–1)1/n, respectively. This indicates that the CV dye adsorption process occurs on heterogeneous surfaces with multilayer that occur through the pores of activated carbon and the magnetic properties of PPAC-Fe3O4 have increased the number of adsorbed CV dye.