Avaliação da eficiência da fotocatálise heterogênea com óxido de zinco na degradação de fármacos.

Abstract

The presence of contaminants remaining after conventional water treatments has taken on a role as a warning in the final quality of water consumed by the population in various parts of the world. An example is the drugs that have been detected in domestic sewage, surface and underground water in low concentrations. Furthermore, in recent months, Brazil has emerged as the Latin American epicenter of the coronavirus pandemic (SARSCov-2), a scenario in which there has been an increase in the sale of medicines in an attempt by the population to remedy or prevent this virus. Such a sharp increase in the use of these drugs, however, could pose risks to Brazil's high biodiversity biomes - an issue that overlaps with the country's precarious sewage treatment situation. Thus, there is a need to implement new technologies that have the capacity to mineralize these remaining contaminants in treated effluents. In this scenario, heterogeneous photocatalysis presents itself as a viable alternative for the degradation of these species, since in such a process chain reactions are triggered that, consequently, generate radicals that will react with organic and inorganic compounds, mineralizing them to CO2, H2O and mineral salts. It is in this context that the present work is inserted, whose main objective was to synthesize and evaluate the efficiency, in heterogeneous photocatalysis, of the zinc oxide (ZnO) catalyst in the degradation of drugs widely used by the population in recent years. The samples were synthesized by the modified Pechini method and then characterized by the techniques of XRD, FTIR and UV-Vis diffuse reflectance. The drugs evaluated were Nitazoxanide, Dipyrone and Paracetamol, both in a pure matrix (distilled water) and in a real matrix (wastewater after physical-chemical treatment). The results indicated that the ZnO samples showed high photocatalytic activity, reaching considerable levels of drug removal under different conditions of the reaction medium – pure solution, mixed solution, solution in treated sewage water.