Aplicação de tecnologias eletroquímicas como alternativa para o tratamento de efluentes de salão de beleza

• Ano de defesa: 2023
• Autor(a) principal: Vieira, Gleilson de França
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA
• Palavras-chave em Português: Eletroquímica; Salão de beleza; Efluente; Oxidação anódica; BDD; Eletrólitos de suporte; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufrn.br/handle/123456789/55335

One of the electrochemical advanced oxidation processes is anodic oxidation, which is very efficient in treating wastewater that contains different organic contaminants. Two beauty salon effluents were collected and treated using electrochemical oxidation and their initial physical-chemical analysis demonstrated an average COD of 1612 and the second of 1496 mg O2 L–1, turbidity of the first effluent of 477 NTU and the second of 1000 NTU in addition to the presence of trace metals such as: iron, copper, chromium and zinc. The experimental analyzes were carried out in a laboratory-scale plant, using an electrochemical flow cell consisting of a circular stainless steel plate as cathode and another containing boron-doped diamond (BDD) as anode, both with an active surface of 69.4 cm2, separated by a distance of 1.7 cm. For each experiment, 1.2 liters of contaminated effluent were placed in the reservoir tank where it was circulated for 360 minutes and samples were collected at specific time intervals through the reaction compartment cell. Electrolyses were carried out applying 10 and 30 mA.cm–2, using different electrolytes (NaCl, Na2SO4 or Na2S2O8) in various concentrations. When comparing the treatments used in the first effluent, the one that had the best efficiency was the analysis with low current density together with the addition of 0.16 M sodium chloride, in which there was an average decrease in COD of 65%. In the treatments of the second effluent, a photochemical cell coupled to the hydraulic circuit was used in a simultaneous process with the electrochemical reactor along with the addition of sodium persulfate. Knowing that the reaction with the use of sodium chloride can form chlorinated substances, leaving the final effluent with high toxicity and in the analyzes with sodium persulfate the acidity index reached pH 2.0, then it is necessary to optimize a process with greater efficiency, better yield and more viable. In the analyzes of the second effluent, we discovered results that clearly showed that 6 h of treatment with Na2SO4 achieved 58% COD removal and 73% less turbidity, with an energy consumption of around 0.52 kWh m3, being the best electrolyte option for treating this effluent by applying 10 mA.cm-2. This way, the final effluents can be disposed of in the sewage system or nature with fewer pollutants.