Comparison between nano zero valent iron supporting onto activated carbon collected via two types of reagents statistically: Carbon for cationic dye removal

Abstract

One of the important substances was the carbon which was used to prepare adsorbents like, Nano zero-valent iron on carbon as supporting materials by sodium borohydride as a reducing agent. Nitric acid was used with heating at a temperature of 90 ° C and stirring for two hours to generate active groups on the surface of the activated carbon. The new zero-valent iron adsorbent was loaded on the surface of the functionalized activated carbon (NZVI/AC) and characterized using X-ray diffraction (XRD), the surface area measurement (SBET), and the Field emission scanning electron microscopy (FESEM). The synthesized (NZVI/AC) was applied for the removal of cationic dye as methylene blue (MB) from simulated wastewater. On the other hand, the adsorption and the kinetic studies for the MB removal were investigated via both kinetic models as the pseudo-first and the pseudo-second-order kinetic models. Also, the initial concentration of the MB adsorption studies was with a concentration of 20 mg/L, the adsorbent dosage of 0.1 g, the contact time of 60 minutes with high uptake value at natural pH solution. It was found that the removal efficiency of the adsorbent NZVI/AC was higher than the AC without Nanomaterial’s with values of 96.70% and 84.16% respectively. It is noted that the removal rate increased almost 12 times in comparison between AC and NZVI/AC. In the kinetic studies; the second-order kinetic model was more favorable than the first-order kinetic model in the adsorption mechanism. Thermodynamically, the Gibbs free energy (ΔG°) was found to be with a negative value indicating the spontaneity of the process, while the change in the entropy ΔS° and the enthalpy ΔH° with positive values indicating the adsorption of MB was an endothermic process. It could conclude that the new adsorbent NZVI/AC had significant potential for the cationic dye removal than the activated carbon AC in the environmental application.