Avaliação do desempenho do carvão activado a base de sabugo de milho e folhas de eucalipto no tratamento de águas residuais

Abstract

Water is a natural and renewable resource through the hydrological cycle, covering 70% of the Earth's surface. Of the total water available, it faces the problem of quality deterioration due to contamination caused by anthropogenic activities. For its safe reuse, technologies such as activated carbon are employed to purify water, protecting the environment and human health. Activated carbons are a form of carbon obtained through physical or chemical activation processes, and they are extremely important materials as they are used as adsorbents in numerous processes. In this study, biochar from corn cob and biochar from eucalyptus leaves were used. The biochar from corn cob was pre-mixed with biochar from eucalyptus leaves in different mass proportions (15%, 30%, and 50%) and subjected to the same activation conditions. To evaluate the effects of the modifications promoted by the pre-mixing, adsorption tests were conducted using water contaminated with methylene blue dye, employing two kinetic models: the pseudo-first order kinetic model and the pseudo-second order kinetic model. It was found that CA1 fits the first-order model, while CA2, CA3, and CA4 fit the second-order model. As the percentage of biochar from eucalyptus leaves in the carbon matrix increases, the tendency to fit the second-order model increases, along with chemisorption. This increase in the mixture percentage led to a reduction in the maximum adsorption capacity of (260, 175, 206, and 170 mg g −1 ) for adsorbents CA1, CA2, CA3, and CA4, respectively.