Magnetized Activated Carbon Prepared by Oak Shell Biowaste and Modified with Nickel Hexacyanoferrate for Selective Removal of Cesium

The activated carbon synthesized by biowaste materials was magnetized by Fe3O4 nanoparticles and then impregnated with nickel hexacyanoferrate. The magnetize composite was identified by various methods including; XRD, FT-IR, TG, VSM and SEM technique and then employed for separation of cesium from aquatic systems. The adsorption capacity was optimized by evaluating different experimental variables including time, pH, dose, and concentration, and the maximal uptake of 135.28 mg g(-1) was obtained. Evaluation of adsorbent selectivity was performed with co-existing cations including Mg2+, Ca2+, Na+, K+ and NH4+. The results revealed that removal process was endothermic, spontaneous, with fast kinetic. The adsorption data was evaluated using Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The data was well described by the Langmuir model. The pseudo first-order, pseudo second-order, Intra-particle diffusion equation and Elovich kinetic models were used to evaluate the kinetic data. The used sorbent regenerated by use of nitric acid solution retained most of its initial capacity.