Tratamento de efluente gasoso ácido de indústria têxtil automotiva por neutralização seguida de sistema biológico

Abstract

Lamination, in the production of automotive coating, is the process that consists of the adhesion of foam to the fabric and uses flame heating in which gaseous effluents with an acid characteristic are released. The growing concern about environmental and health problems leads to the need to treat this effluent in the industry. Said gas is a mixture of carbon dioxide, hydrochloric acid and others. This study aims to develop a proposal of adequate treatment for this effluent, which is economically feasible, easy to operate and environmentally correct. Pretreatment consisted of using chemical absorption columns with different basic reagents such as sodium hydroxide, calcium hydroxide, calcium oxide, calcium carbonate, for the neutralization of acids, followed by the passage of the gas through a biological system, composed of microalgae, which are capable of consuming carbon dioxide when performing photosynthesis. The methodologies used were classical analyzes, such as acid-base titration of the crude and treated effluent, as well as optical microscopy for cell count in the control of the microalgae population. The results found for the acidity of the crude effluent ranged from pH 2.70 to 2.88. The removal efficiencies of the neutralizing reagents varied from 35.7% to 62.5%. The microalgae biofilter, tested as biological treatment, had favorable aeration behavior with the crude effluent, growing from 4.22 x 105 to 1.17 x 106 cells∙mL-1. Therefore, more in-depth studies of the biological system will be needed to see if there is any removal efficiency of the acid gases.