Aplicação da fotocatálise utilizando eletrodos de nanoporos de dióxido de titânio como fotocatalisador sob luz para tratamento da água contaminada com pesticida

Abstract

Among the different types of pesticides, one class that has gained prominence is neonicotinoids, which act as a selective agonist of nicotinic acetylcholine receptors in insects, with consequent nervous hyperactivity and nervous system collapse. Despite improving agricultural production, pesticides have direct impacts on human health and the environment. In this context, this work investigated the treatment with heterogeneous photocatalysis using TiO2 nanotubes as photocatalysts with the aim of verifying the efficiency of this material in oxidizing the pesticide Imidacloprid and reducing the products generated in the reaction medium, since this process has stood out for its its high destructive capacity for organic molecules. At the same time, ecotoxicological tests with model organisms were carried out to indicate whether the treatment resulted in a reduction in the toxicity of the compound, together with UV-Vis analysis. Therefore, the objective of this work is to study the efficiency of nanoporous TiO2 photocatalysts in the photocatalytic degradation of the insecticide Imidacloprid. The UV-vis spectra were able to demonstrate the wavelength that indicates the presence of the pesticide, which in this case is 280 nm, where during the treatment time it varied from 0-180 minutes distributed over 10 times. Degradation rates during the process were also observed, the results of which varied at the initial times from 67 to 77% and at the end from 96 to 99%. Another important point was the degradation kinetics determined, which presented acceptable linearity of approximately 0.98 and the percentage of toxicity tests during treatment that achieved results greater than 80% of nauplii survival. Therefore, the results achieved demonstrate that the photocatalysis technique with the TiO2 electrode is efficient in the degradation of the pesticide Imidacloprid.