Adsorption of Indigo Blue (3h-indol-3-one 2 - (1,3-dihydro-3-oxo-2H-indol-2ylidene)-1,2-dihydro) in bark of green coconut (Cocos nucifera)

• Grant number: 11/21511-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: January 31, 2013
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Patricia Antonio
• Grantee: Lívia Fiorotto Zeferino
• Host Institution: Escola de Engenharia Mauá (EEM). Instituto Mauá de Tecnologia. São Caetano do Sul , SP, Brazil

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, 5 and 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 (10, 25 and 40)oC. 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. The stability of the modified adsorbent against different eluents (HCl, HNO3 and NaOH) will be studied. (AU)