Remoção de corantes a partir do acetato de celulose modificado tioacetamida

Abstract

Dyes are responsible for part of the environmental contamination caused by the release of industrial effluents, which, without proper treatment, cause an ecological imbalance. Tartrazine yellow and ponceau red 4-R are widely used in the food and pharmaceutical sector, due to this great use and the preservation of the environment, the removal of dyes from water becomes of fundamental importance. In this sense, this work aimed to chemically modify cellulose acetate (CA), which is a low-cost material, with thioacetamine, which was applied as an adsorbent of these dyes in an aqueous medium. Pure AC and AC with thioacetamide (ACTio) were characterized by infrared spectroscopy (IR). The adsorption tests were performed at different time intervals and the amount of adsorbed dye was determined by UV/Visible spectroscopy. The IR spectra made it possible to observe and classify the main bands related to the vibrations characteristic of the functional groups present in the structure of AC and ACTio, proving the incorporation of thioacetamide. The adsorption tests for tartrazine yellow dye show a removal of 69% using pure Ac and 94.8% using ACTio, and for ponceau red dye 4R a removal of 67% for pure AC and 92% removal. for ACTio. The adsorption data fitted well to the Langmuir isotherm model, with qm values ​​from 0.37 mol L-1 h- 1 to 0.33 mol L-1 h-1 for the tartrazine yellow dye and for ponceau red 4R, respectively, as ACTio adsorbent.