Síntesis y caracterización de carbón activado a partir de los residuos orgánicos de la musa x paradisiaca mediante activación química

Abstract

The purpose of this research was to determine the optimum concentration of H3PO4 in the activation of char derived from plantain (Musa x paradisiaca) residues for chromium removal. For this purpose, the residues were dried, crushed and carbonized using the Thermal Pyrolysis Batch Reactor at 400 degrees Celsius. Subsequently, activation was carried out with phosphoric acid (H3PO4) at different concentrations (T1-85, T2-55, T3-35%), each with 4 replicates. The characterization of the activated carbon was performed by FTIR Infrared Spectroscopy to identify the presence of functional groups. The adsorption capacity of the carbon was evaluated by a colorimetric method. A calibration curve was prepared using potassium dichromate to prepare a stock solution (K2Cr2O7) and then dilutions of 0.05; 0.125; 0.250; 0.500; 0.750; 1.00; 2.50; and 5.00 µg chromium/ml water, titrated with diphenylcarbazide and measured in a spectrophotometer. Activated carbon filters were prepared and exposed to a solution with a chromium concentration of 10 µg. Diphenylcarbazide was added and read in the spectrophotometer. The yield of the process was 3.36%. In the FTIR infrared analysis, several functional groups were identified, but all samples showed a strong signal at a wavenumber of T1: 987.375, T2: 987.375, T3: 995.089 [cm-1], indicating the presence of phosphate functional groups. Regarding the adsorption capacity, the best result was obtained with the T1 treatment, with an adsorption percentage of 89.645%. The statistical analysis concluded that there are significant differences in chromium adsorption according to the concentration of the activating agent, with treatment T1 (H3PO4 85%) being the most effective. It is recommended to perform the analyses with potassium dichromate on the same day to avoid a wide margin of error in the results.