Publicação
Olive pomace effluent treatment by adsorption process and peroxy-electrocoagulation
| Resumo: | The effluent of the olive bagasse oil extraction has a highly toxic nature, due to the high concentration of phenolic compounds (8.13 g L-1), COD (86.41 g O2 L-1), acid pH (4.84) and low biodegrability (BOD5/COD = 0.14), making it impossible to apply biological treatments. It is an effluent of dark reddish appearance, with strong odor and difficult to treat. Thus, the aim of this work was to perform the treatment of effluent to reduce the concentration of pollutants and harmful elements to the environment using the method by Adsorption with Activated Carbon (AC) and Peroxy-electrocoagulation (EC) with aluminum electrodes. To evaluate the treatment with both techniques, the physicochemical characterization of the natural effluent and after treatment was performed. The adsorption tests were carried in two stages, at the first stage was evaluated the concentration of AC, agitation time and agitation speed. However, for the second stage, the agitation speed was not considered relevant for the development of effluent treatment, being analyzed only the concentration of AC and agitation time. Based on the Variance Analysis Table (ANOVA) and the Response Surface Methodology (RSM), it was possible to conclude that for adsorption experiments with AC, the adsorbent concentration was the most significant factor of the process. Therefore, with the increase in the amount of AC added to the system, there was greater removal of phenolic compounds and COD. After treatment by adsorption with AC, a reduction of 32.2% of phenolic compounds and 28.4% of COD was obtained. For the peroxy-EC tests, the concentration of hydrogen peroxide (H2O2), the current density (DC) and the initial pH were used as parameters. When analyzing the Tables ANOVA and RSM, it was noticed that for the peroxy-EC experiments the parameter with the most significance was the concentration of H2O2 added to the system. At the end of the peroxy-EC process, a 90.4% decrease in phenolic compounds and 19.6% of COD was achieved. The adsorption treatment with AC presented insufficient removal of phenolic compounds and organic load (COD), considering the proposed limits for the factors studied. While the peroxy-EC process with aluminum electrodes showed satisfactory decrease in the phenolic compound concentration. However, for both processes, there is space for improvement in the efficiency of the processes. Therefore, future works will be important in the search for adequate treatment for this type of effluent. |
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| Autores principais: | Tesuka, Leticia Harumi |
| Assunto: | Adsorption Chemical oxygen demand Olive pomace oil Peroxyelectrocoagulation Phenolic compound |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | The effluent of the olive bagasse oil extraction has a highly toxic nature, due to the high concentration of phenolic compounds (8.13 g L-1), COD (86.41 g O2 L-1), acid pH (4.84) and low biodegrability (BOD5/COD = 0.14), making it impossible to apply biological treatments. It is an effluent of dark reddish appearance, with strong odor and difficult to treat. Thus, the aim of this work was to perform the treatment of effluent to reduce the concentration of pollutants and harmful elements to the environment using the method by Adsorption with Activated Carbon (AC) and Peroxy-electrocoagulation (EC) with aluminum electrodes. To evaluate the treatment with both techniques, the physicochemical characterization of the natural effluent and after treatment was performed. The adsorption tests were carried in two stages, at the first stage was evaluated the concentration of AC, agitation time and agitation speed. However, for the second stage, the agitation speed was not considered relevant for the development of effluent treatment, being analyzed only the concentration of AC and agitation time. Based on the Variance Analysis Table (ANOVA) and the Response Surface Methodology (RSM), it was possible to conclude that for adsorption experiments with AC, the adsorbent concentration was the most significant factor of the process. Therefore, with the increase in the amount of AC added to the system, there was greater removal of phenolic compounds and COD. After treatment by adsorption with AC, a reduction of 32.2% of phenolic compounds and 28.4% of COD was obtained. For the peroxy-EC tests, the concentration of hydrogen peroxide (H2O2), the current density (DC) and the initial pH were used as parameters. When analyzing the Tables ANOVA and RSM, it was noticed that for the peroxy-EC experiments the parameter with the most significance was the concentration of H2O2 added to the system. At the end of the peroxy-EC process, a 90.4% decrease in phenolic compounds and 19.6% of COD was achieved. The adsorption treatment with AC presented insufficient removal of phenolic compounds and organic load (COD), considering the proposed limits for the factors studied. While the peroxy-EC process with aluminum electrodes showed satisfactory decrease in the phenolic compound concentration. However, for both processes, there is space for improvement in the efficiency of the processes. Therefore, future works will be important in the search for adequate treatment for this type of effluent. |
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