Remoção de fenol em amostras de água utilizando persulfato ativado por ferro zero suportado em biochar

• Ano de defesa: 2023
• Autor(a) principal: Souza, Joyce Azevedo Bezerra de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA QUÍMICA
• Palavras-chave em Português: Tratamento de efluentes; Processos oxidativos avançados; Persulfato de sódio; Ferro de valência zero; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: https://repositorio.ufrn.br/handle/123456789/54707

Modernization, high population growth and accelerated production of inputs are triggering the increase in the generation of industrial effluents, which represents a serious problem globally, as they can contaminate water, soil and air. The oil industry is one of the main sources of water contamination, and its products and by-products have numerous contaminants with toxicological, carcinogenic and mutagenic properties, which can compromise the quality of the environment and cause negative impacts on human, animal and plant health. Phenol is a representative of the pollutants of this industry, being present in effluents such as water produced from petroleum and in refineries. For the treatment of water contaminated with this pollutant, Advanced Oxidative Processes (AOP) are being widely used. Therefore, this work aimed to treat water contaminated with phenol through a POA using sodium persulfate (PS) as an oxidant, and the combination of zero valence iron (ZVI) supported on biochar (BC) as a form of of persulfate activation. The biochar was obtained by pyrolysis (300°C for 1 h, with a heating rate of 10°C. min-1), using the peel of the fruits of Calotropis procera as biomass, and the ZVI was obtained by the chemical reduction method. BC, ZVI and BC-supported ZVI (BC/ZVI) were structurally, compositionally and morphologically characterized by XRF, XRD, SEM-EDS, FTIR, zeta potential analysis, particle size and polydispersion index. Regarding the oxidation experiments, an experimental design was carried out in which the variables analyzed were the concentration of the oxidant ([PS] = 1 to 9 mM) and BC/ZVI ([BC/ZVI] = 1 to 5 g.L-1). Then, the process optimization was performed, studying the concentration of the oxidant ([PS] = 5 to 13 mM), activator ([BC/ZVI] = 3 to 7 g.L-1) and pH (3.0 to 11.0). It was also possible to compare the activating agent with the commercial Fe0, seeking to confront them with the proposed AOP. The results obtained with the characterization of the materials confirm that the synthesized biochar was similar to that synthesized by other works in the literature, being a carbonaceous material, with pores in its structure and that presented several oxygenated groups on its surface. The synthesized ZVI presented structures with irregular shapes and the particles tended to agglomerate, similar behavior to that found in other literary studies. The BC/ZVI was characterized as a material that had porosity, functional groups on its surface and that the ZVI accommodated efficiently on its surface, allowing these particles to be available for oxidation. The results of the oxidative treatment indicated that the proposed PS/BC/ZVI system is efficient for phenol degradation, since good phenol removal results were obtained. From the planning carried out, the best point obtained was test 4, with the optimal conditions of [PS] = 9 mM and [BC/ZVI] = 5 g.L-1 and pH = 3.0, having the rate of maximum removal of 89.99% removal. The degradation of phenol using PS activated with BC/ZVI obtained in this work is efficient for the treatment of effluents, in addition to its application to reduce toxicity in cases of release into bodies of water without proper treatment.