Adsorção do corante azul de metileno (AM) em bioadsorventes produzido a partir do resíduo do buriti (Mauritia flexuosa L. f.)

Abstract

In the current scenario, using natural resources rationally and with minimal waste is the policy spoken by all countries, in this sense, for biomass, one solution is to use it as a bioadsorbent to remove dyes in an aqueous medium. The objective of the work is to study the bioadsorbent from buriti (Mauritia flexuosa L. f.) waste to remove methylene blue. Initially, in natura bioadsorbents were produced (only unitary processes) and bioadsorbents modified with acid and base (H2SO4 and NaOH), for characterization the techniques of Boehm titration, x-ray diffraction, ultraviolet visible spectroscopy and electron microscopy were used. scan. Of 50 kg of biomass, 36 kg were angiosperm and 14 kg were bark and endocarp, which were used to produce the biosorbent. The PCZ was 6, 7 and 3, the optimum mass point was in natura 0.200 mg, 0.200 mg for the modified with the base and 0.700 mg for modified with acid, the isotherms used were those of Freundlich, it presented a better adjustment with the R2 of 0.972 for in natura and Langmuir for the modified acid 0.957 and modified basic 0.975. The ideal contact time to reach the observed equilibrium was 15 minutes, while the optimal dose of adsorbent was 16 g L-1, for the MB adsorbent it was triple this value, 48 gl-1. The maximum adsorption capacity of bioadsorbent was 98.50 mg g-1 for in natura, 210 mg g-1 for the basic modified and 294 mg g-1 for the acid modified, observed at pH 6 and 25ºC, for desorption showed It is ineffective at pH above 6 and the best values were at pH 2 for the in natura bioadsorbent. In the fixed bed filtration experiment, all bioadsorbents removed 100% of the dye, however, the in natura and basic bioadsorbents released residues of organic molecules, so the best result was for the acid modified one. Therefore, buriti biomass proved to be positive in terms of its use as a bioadsorbent, when compared to the literature it appears to be a viable option for removing dye from effluents, and can be used for adsorption of methylene blue in the form of a fixed bed.