44ª Reunião Anual Virtual da SBQ

Char products, extending their potential applications, as pharmaceutical and cosmetic sectors. This work aim to determine kinetic parameters of the adsorption of tartrazine dye (TD) in oat biochar (BC). The residual biomass of oat, was pyrolyzed at 400 °C (± 5) for 30 min, generating BC, that was crushed (≤ 0.01 mm), washed with distilled water and dried at 60 °C (± 3). The adsorption of TD in BC, were done in becker cups containing 50 mL of TD solutions (6.2 to 74.3 mg/L), at 25, 40 and 55 °C, 100 mg of adsorbent for 30 min. Aliquots were collected every 5 min, centrifuged and the absorbance was determined in 420 nm.
The best fit was obtained for the pseudo-second-order kinetic model (R2: between 0.98 and 1.00). The highest adsorption capacity was shown for the temperature of 40 °C (qe (exp.): 5.27 and qe (teor): 5.40 mg/g). This suggests that this sorption system step may be involving valency forces through sharing or exchange of electrons between sorbent and sorbate. Pseudo-second order kinetic model suggests that chemical adsorption of TD by BC is the dominant mechanism, involving electrostatic attraction.