USE OF KAPOK POD FOR ADSORTIVE REMOVAL OF RHODAMINE B IN WATER SOLUTION

Irregular disposal of waste from activities can cause several environmental problems, therefore, there has been a strong trend in the development of research and processes that minimize negative impacts. Adsorptive methods have gained in the treatment of effluents, since this technique is efficient in removing pollutants harmful to the environment; Contaminants have low biodegradability capacity, resistance to conventional treatments and often under low conditions. The use of biomass as adsorbent material tends to reduce the costs of the adsorptive process due to its availability and abundance. Among the persistent pollutants, there is the compound Rhodamine B, which is a cationic dye, which, in addition to being difficult to remove, presents a health risk. From the biomasses from agricultural activities, we can mention the kapok pod, which is considered one of the few residues originating from Paineira, since the fruit capsule is one of the only items that do not have an application described in the literature. Therefore, making use of this solid residue as an adsorbent, provides the valorization of a material that was previously seen only as waste. In this context, the objective was to evaluate the kapok pod as an adsorbent material for the removal of Rhodamine B in aqueous solutions. Through the characterization techniques employed, such as SEM (Scanning Electronic Microscopy), FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffractometry), zeroload pH and TGA/DTG (Thermogravimetric Analysis) it was possible to know the chemical and morphological characteristics of the adsorbent We also evaluated the adsorption kinetics, the interference of variations in adsorbent mass and adsorbate concentration and pH influence, as well as the possible interferences of the adsorptive process when applied in real water. It was observed that the kapok pod has a morphological structure composed of characteristics that suggest a high adsorptive potential by indicating a high surface area. The functional groups observed were characteristic of lignocellulosic materials and indicated the possibility of interaction from hydrogen and/or dipole-dipole bonds. As it is a material of natural plant origin, its amorphous characteristics were confirmed, in addition, the thermogravimetric analysis shows the thermal stability of the natural material. In the affinity tests, it was possible to observe a strong interaction in all applied pH ranges. At natural pH, removal was greater than 89% at 5 mg.L-1 of dye concentration and around 71% at 100 mg. L-1 . In the test in real water, the non-selectivity of the material was observed, due to the reduction of the adsorptive capacity in salt water, but still showing a removal percentage above 59%, under more severe conditions. In the kinetic study it was observed that in 240 min about 80% of the material adsorptive capacity was reached. Such results corroborate the use of this material as an environmentally friendly alternative in a dual carriageway, both in terms of the recovery of solid waste and its potential in processes of removing pollutants in the aqueous phase.