Huitle, Carlos Alberto MartinezCosta, Letícia Gracyelle Alexandre2024-01-222024-01-222023-07-27COSTA, Letícia Gracyelle Alexandre. Aplicação da oxidação eletroquímica para a geração de oxidantes fortes, geração de produtos de valor agregado e degradação de paracetamol, cafeína e olanzapina em efluentes sintéticos. Orientador: Dr. Carlos Alberto Martinez Huitle. 2023. 141f. Tese (Doutorado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2023.https://repositorio.ufrn.br/handle/123456789/57356Electrochemical treatments of effluents are facing a paradigm shift; instead of achieving complete mineralization of organic pollutants, researchers are seeking to give economic value to the products generated during the degradation process. One of the products that are electrogenerated in the electrochemical oxidation process is volatile fatty acids. These acids are commodities used in various industrial segments, such as the food, textile, and pharmaceutical industries. This work aims to evaluate the efficiency of electrochemical oxidation in the degradation of pharmaceutical compounds, seeking to find the best conditions for both the removal of these organic pollutants and the electrogeneration of volatile fatty acids. The results achieved during the research are divided into three chapters. The first chapter presents a review of the literature on the production of persulfate and peroxophosphate oxidants and their application in the removal of pharmaceutical contaminants. The second chapter presents an evaluation of the oxidizing power of electrogenerated persulfate and peroxophosphate solutions for ex-situ application. It was observed that the increase in current density is proportional to the increase in the concentration of the electrogenerated oxidant. In the ex-situ oxidation process, paracetamol removal of 46.66% for persulfate and 47.15% for peroxophosphate was achieved. The best condition for this type of application was using the lowest contaminant volume/oxidant volume ratio (0.5). The third chapter presents the results found in the electrochemical oxidation of the pharmaceutical compounds paracetamol, caffeine, and olanzapine. The experiments were carried out in a cell using a Boron-Doped Diamond (BDD) anode, using sulfuric acid and 0.5 mol L-1 sodium sulfate as supporting electrolytes. The process of electrochemical degradation and acid formation was monitored by High Performance Liquid Chromatography. It was possible to observe that by using sulfuric acid as an electrolyte, the degradation of the compounds was achieved more quickly, as the acidic medium helped in the solubilization of contaminants and favored the production of persulfate. Additional experiments with perchloric acid were carried out under the same conditions to evaluate the influence of the sulfate radical on degradation. When comparing the experiments, it was proven that the sulfate radical is mainly responsible for the efficiency of the process. The Total Organic Carbon results showed that despite the complete degradation of the pollutant, the organic matter present in the effluent was not completely consumed, indicating that new organic products were produced. Through chromatographic analysis, the formation of acetic acid, formic acid, and oxalic acid was verified in experiments with sulfuric acid as an electrolyte. For experiments with sodium sulfate, acetic, formic, tartaric, and salicylic acids were found. Germination experiments with lettuce seeds were carried out as initial tests, seeking to evaluate the toxicity of the effluent after treatment for the future use of this effluent in agricultural reuse. Only the seeds that were watered with the effluent treated with sodium sulfate germinated. It is concluded that electrochemical oxidation is an efficient process both for the generation of oxidizing species for in situ and ex situ applications and for the electrogeneration of carboxylic acids.Acesso AbertoOxidação eletroquímicaFármacosPersulfatoPeroxofosfatoEletrogeração de ácidos carboxílicosdoctoralThesisCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA