Degradação de Diclofenaco de sódio pelos processos de ozonização e fotocatálise heterogênea.

Abstract

One of the consumption chains that has been most compromising the quality of water resources, with an increase in the generation of waste and inadequate disposal, are drugs. Despite having a vital function, drugs when administered in the wrong dose and prescription, can be harmful to humans and animals, as they generally have a low absorption capacity of the compounds. The main entry route of drug residues into the environment is the discharge of domestic sewage, treated or fresh, into water courses. Advanced Oxidative Processes (POAs) have received prominence as an alternative wastewater treatment process, as they are efficient methods that reduce environmental impacts. Therefore, the objective of this study was to evaluate the use of Advanced Oxidative Processes (POAs) of Catalytic Ozonation, Heterogeneous Photocatalysis and Photocatalytic Ozonation, using TiO2, as treatment of effluents containing the drug diclofenac sodium, in addition to analyzing the toxicity of effluents, as well as other chemical parameters, before and after treatments. As a result, high removal efficiencies were achieved with the use of catalytic ozonation and photocatalytic ozonation, reaching efficiencies between 95~99%. The Heterogeneous Photocatalysis treatment was the one that reached the lowest efficiencies of removal of this drug, reaching about 20%. In general, the processes involving the use of ozone had the pH gradually decreased while the conductivity was increased, while heterogeneous photocatalysis remained at neutral pH. Regarding COD, a removal of up to 70.58% was achieved using only ozone, while Heterogeneous Photocatalysis and Photocatalytic Ozonation obtained a removal efficiency of up to about 40%. Although some treatments reduced mitotic indices in Allium cepa, there were no chromosomal alterations and mutations statistically different from the negative control, so it cannot be said that the treatments caused cytotoxic, genotoxic or mutagenic effects in this species. For phytotoxicity, it was also not verified that the treatments had produced toxic effects for the seeds, only one of the analyzed bioindicators showed a statistical difference in one of the treatments used, demonstrating that the Lactuca Sativa species was the most sensitive of all for the germination index.