Study of preconcentration and removal Indigo blue (3h-indol-3-one 2-(1,3-dihydro-3-oxo-2h-indol-2ylidene)-1,2-dihydro in industrial effluents using the bark of green coconut (Cocos Nucifera) as a bioadsorbent

Abstract

Considering that about 240 000 tons of coconut shells are launched every year in landfills and that decomposition occurs slowly peel, studies for the reuse of this material will be made in order to use it as a bioadsorbent for the removal of the reagent Indigo Blue, dye the textile industry.The Indigo Blue (3H-indole-3-one,2-(1,3-dihydro-3-oxo-2h-indol-2ylidene)-1,2-dihydro) is a natural vegetable dye and can be determined by spectrophotometry. Studies of adsorption of Indigo Blue in green coconut fiber shell will be performed at different pH values (1, 4,7 e 12). Known mass of solid phase will be put in contact with solutions of known concentrations of Indigo, stirring for a certain time interval at different temperatures. The concentration of dye adsorbed is calculated by considering the difference between the initial concentration and the residual concentration in the supernatant solution, both obtained from absorbance measurements.From the kinetic study will be found adequate time to connect the system to a maximum adsorption and allow the implementation of three simplified kinetic models, pseudo-first order, pseudo-second order and intraparticle diffusion. Different isotherm models will be applied: Langmuir, Freundlich and Dubinin-Radushkevich models and the results will be discussed.This work will be divided into three stages: a) bench, b) in a glass column containing the adsorbent, c) applying the method of flow injection analysis (FIA) with a column containing the solid phase. This last step aims at determining and quantifying the dye adsorbed, in addition to expanding the scale of the process, minimizing the consumption of reagents, mechanization / automation of chemical analysis, reducing costs, analysis time and sample handling, leading to a smaller risk of contamination. The qualitative and quantitative characterization of the modified support is performed by the analytical technique Infrared Spectroscopy. (AU)