Aplicação do processo oxidativo avançado utilizando reator foto-ozonizador no tratamento de efluente proveniente de uma ETE: cinética de degradação e caracterização físico-química

Abstract

Advanced Oxidation Processes (AOPs) can be more efficient in the treatment of emerging pollutants and in the degradation of organic compounds due to their high oxidation potential. Unlike conventional treatments that generate byproducts such as sludge, AOPs transform most organic compounds into carbon dioxide, water and inorganic ions. This work aimed to characterize and identify the degradation kinetics of an effluent from a Sewage Treatment Station in Francisco Beltrão – PR, using the AOP O3/UV. The effluent was treated in a photo-ozonizing reactor at different pH ranges: acidic (3.00), neutral (7.41) and basic (9.00). Samples were collected every 15 minutes during 180 minutes of treatment and evaluated for pH, color, turbidity and Chemical Oxygen Demand (COD). The degradation kinetic constants for color and COD were determined using the pseudo-first order model. The toxicity of the effluent before and after treatment was evaluated using the bioindicators Artemia salina and Eisenia fetida. Neutral pH showed better treatment efficiency, with reductions of 38.75% in color, 73.18% in COD and 60.91% in turbidity; however, the acidic pH was more efficient in reducing turbidity, with 67.44%. The kinetic constants for neutral pH were 0.0027 min⁻¹ for color and 0.0067 min⁻¹ for COD. In terms of toxicity, the effluent was not toxic to Eisenia fétida, but Artemia salina was more sensitive to the toxicity of the effluent.