Análise de adsorção de dicromato de potássio por carvão ativado produzido do pó de quiabo (Abelmoschus esculentus)

Abstract

Water pollution is a subject that has always been highlighted in academia, as it is an essential resource for human life. Its contamination by heavy metals and dyes is a subject that deserves special attention, since these materials are harmful to human beings even in low concentrations. The objective of this research was to evaluate the adsorption capacity of activated charcoal obtained from okra powder as an adsorbent for potassium dichromate dye. TGA, FRX, DRX analyzes were carried out for okra powder and activated charcoal, UV-VIS analysis for okra powder and potassium dichromate, and finally, PCZ and adsorption assays for activated charcoal, considering the following parameters: influence of pH, influence of mass and influence of contact time. The thermal analysis of okra powder highlighted its characteristics as an organic material with a polymeric chain, while activated carbon had good thermal stability, with approximately 20% of ashes still remaining at the end of the experiment. The FRX indicated that the main elements of the chemical composition of okra powder and activated charcoal were K2O, CaO, P2O5, MgO, SO3, Si2O and Fe2O3. In XRD, an amorphous characteristic of okra powder was observed, while coal showed peaks with the respective predominant elements. The zero charge point test (PCZ) determined the positive character of activated carbon, where better results were obtained with acidic pH (pH = 2). In the adsorption test, activated carbon reached a removal rate of 86.31% under ideal conditions, with a satisfactory removal rate of 50.09% after the first desorption cycle. The adsorption results of this research showed that activated carbon has great application potential for removing dyes from treated water.