Atenuação do cobre presente em efluente sintético utilizando bioadsorvente da cultura algodoeira.

Abstract

This study aimed to accomplish the mitigation of heavy metal copper, present in synthetic wastewater, using the solid residue of the cotton crop farming as bioadsorbent in the process of biosorption. The work comprised the following steps: (i) grinding the solid waste land; (II) characterization of agricultural solid waste, determining the density, determination of functional groups by Boehm group by infrared spectroscopy Fourier transform, (III) completion of study of the biosorption process, including analysis of variance, kinetic study and obtain the isotherms. The results showed that the solid residue of the cotton crop farming has low bensidade 0,27 mg.L"1. By the method of Boehm observed that there is a predominance of phenolic groups 1,05 N. The groups that present in smaller quantities are carboxylic acids with a concentration of 0,14 N. The infrared spectrum showed OH bonds that are involved in the removal of copper. It was observed that the equilibrium time was reached before the first 30 minutes of contact, the RSA has proved very efficient in the absorption of copper ion, removing 95% of the metal present in synthetic wastewater, reducing the amount of copper beiow the limit maximum allowable (1mg.L"1). The study of kinetics showed that the model represents the pseudo second order reaction kinetics. The Langmuir and Freundlich isotherms are linear type and the experimental data fit better the Freundlich model. The highest percentage removal of copper ion (96%) was observed at concentrations higher than 12 mg.L"1.