Modificações químicas de substratos naturais e seu uso para a remoção de formaldeído em soluções aquosas

Abstract

Formaldehyde is a chemical substance with harmful characteristics to humans, but it has wide application in many areas today. One of them is the preservation of dead bodies to be used in studies anatomy laboratories. The high cost of disposal of these solutions at the Institute of Biological Sciences at the Juiz de Fora Federal University serves as a stimulus work, consisting in the treatment of formaldehyde solutions after an adsorption process using cellulose and its derivatives as adsorbent. Cellulose derivatives are synthesized starting from microcrystalline cellulose and sawdust, but leans the study to the use of sawdust, aimed at greater cost-effectiveness. Some parameters were analyzed in order to achieve optimization of the process, obtained at a temperature of 70 ° C for 28 hours, at pH 6 using a ratio of the substrate mass/volume of solution equal to 202,5 mg/mL. After studies of adsorption isotherms, the best description of the process was achieved by Freundlich model, which considers the adsorption held in multilayer through heterogeneous systems. The study concludes that the sawdust is able to adsorb about 65% of formaldehyde solution and the organic matter contained in solution influences positively the process of adsorption. In addition, colorimetric scale is made, that allows the technicians of the anatomical laboratories control the concentration of formaldehyde in the tanks.