Preparation and evaluation of adsorption properties of the magnetic bagasse

The presence of toxic elements in the aquatic environment has been of great concern because their toxicity at lower concentrations and also they are cumulative and carcinogenic. Toxic elements are absorbed and stored in animal and vegetable tissues, for instance, uranium radionuclides. Radioactive uranium waste is generated at hospitals and universities. Furthermore uranium is used as fuel for nuclear power plants. There are some methods available for the removal of metal ions from aqueous solutions. These are ion exchange, solvent extraction, reverse osmosis, precipitation and adsorption. The last one, adsorption, has directed the research of new materials with good removal capacity. The purpose of this paper was to study the preparation of magnetic bagasse, which consisted of sugarcane bagasse as polymeric matrix with magnetite nanoparticles core. These particles have presented superparamagnetic properties. Some studies were carried out such as time required for the uranium-bagasse equilibrium in the interval from 5 to 90 min, the effects of biomass piece size (Φ < 0.64, 0.64 <= Φ <9.61 and Φ > 9.61)mm2, pH in the intervals from 2 to 5 and 10, stirring speed from 240 to 500 r.p.m. and adsorbent dose from 2 to 25 g.L-1. The efficiency of magnetic bagasse for the removal of U(VI) was 94%. (author)