Adsorptive Removal of Basic Green Dye from Aqueous Solution Using Humic Acid Modified Magnetite Nanoparticles: Kinetics, Equilibrium and Thermodynamic Studies

摘要

In the present study humic acid modified magnetite (HA-Fe3O4) nanoparticles as a novel magnetic adsorbent was synthesized by in situ co-precipitation method for malachite green (MG) remediation. The physio-chemical properties of the prepared nanoparticles were fully examined by using FTIR, SEM-EDX, XRD and UV-Vis, analysis. The pH(pzc), specific surface area and suspension stability in aqueous system of the synthesized Nps were also evaluated. The various characterization revealed that HA-Fe3O4 was effectively synthesized and HA effectively control aggregation and oxidation of Fe3O4 in aqueous system. The XRD result reveals that the synthesized materials have a crystal size of 9.17 and 11.21 nm for HA-Fe3O4 and Fe3O4 Nps respectively. The operational parameters on the removal of MG by the synthesized Nps were also evaluated. The temperature dependence data also revealed that MG sorption process was feasible, spontaneous and endothermic. The MG adsorption rates were described by the pseudo 1st order model and Freundlich isotherm model. The maximum adsorption monolayer capacity of HA-Fe3O4 and Fe3O4 was 79.3 mg/g and 62.2 mg/g respectively. The reusability is an important factor to evaluate the HA-Fe3O4 and Fe3O4 in real applications and the optimum desorption was attained at 0.1 M of HCl for both Nano-sorbents. Based upon the results, the prepared Nano sorbent could be efficient for the removal of different cationic dyes from waste water.[GRAPHICS].