Abstract

MATIAS, Caroline Aparecida; OLIVEIRA, Leonardo Jonathan Guisolphi Gomes de; GEREMIAS, Reginaldo  and  STOLBERG, Joni. BIOSORPTION OF RHODAMINE B FROM AQUEOUS SOLUTION USING Araucaria angustifolia STERILE BRACTS. Rev. Int. Contam. Ambient [online]. 2020, vol.36, n.1, pp.97-104.  Epub Dec 22, 2020. ISSN 0188-4999.  https://doi.org/10.20937/rica.2020.36.53282.

This study evaluated the removal of Rhodamine B dye by biosorption using Araucaria angustifolia sterile bracts. It also aimed to evaluate the treatment of a synthetic wastewater holding that dye. The biosorbent was characterized by infrared spectroscopy and thermogravimetric analysis. Equilibrium biosorption studies were made with the exposure of biosorbent to aqueous solutions of rhodamine B at different pH and initial concentrations. Removal tests for wastewater containing dye were performed with the bracts, and efficacy was assessed by the percentage of uptake of dye and bioassays. The infrared characterization showed peaks that are features to groups on carbohydrates and lignin, the major components in bract composition. The biosorption equilibrium studies presented acid media as the best condition for dye removal. The rate-controlling step of the biosorption was found to be governed by chemical processes (second order kinetics) and shown to be a heterogeneous biosorption based on the fit to the Freundlich equation model. The treatment for synthetic wastewater (125 mg/L) reduced the mass of rhodamine B by 96 % and caused a decrease of toxic effects. The results show that sterile bracts can be considered as a low-cost alternative biosorbent to be applied on the removal of water pollutants and treatment of potentially toxic effluents.

Keywords : Allium cepa; biosorbent; dye; pollution.