Technical, economic, and environmental evaluation of different Fenton-based processes for treating hospital wastewater
| Autor: | Grisales Cifuentes, Claudia Mildred |
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| Přispěvatelé: | Serna Galvis, Efraím Adolfo, Torres Palma, Ricardo Antonio |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Repositorio UdeA Universidad de Antioquia instacron:Universidad de Antioquia |
| Popis: | Advanced Oxidation Processes (AOPs) are gaining attention to remove pharmaceuticals from hospital wastewaters (HWW). In this study, the feasibility of applying Fenton-based technologies (carbocatalysis and photo-Fenton), and assessing their technical, economic, and environmental performance was evaluated. For the technical criterion, Box-Behnken experimental designs were applied; to establish the economic aspect, reagents and electric energy consumptions during the operation of processes were considered, while the environmental impact was determined using life cycle assessment. Initially, it was tested a carbocatalytic process using a biochar from palm fiber wastes to activate different oxidants (hydrogen peroxide, peroxymonosulfate, and persulfate) during the elimination of three pharmaceuticals (valsartan, cephalexin, acetaminophen) belonging to diverse therapeutic groups. Secondly, the photo-Fenton process, at natural pH, using peroxymosulfate in place of hydrogen peroxide for the elimination of a representative pharmaceutical (valsartan) in simulated and actual HWW, was tested. The modification of the process by the addition of citric acid was also evaluated. Finally, a comparison between carbocatalysis and photo-Fenton (using Fe(II)+PMS+UVA with citric acid) was done. Carbocatalytic treatment was more efficient against compounds, such as valsartan, recalcitrant to conventional oxidants and hardly adsorbed on the carbonaceous material. This process involved hydroxyl radical and singlet oxygen in the target pollutant degradation. Under optimal conditions, the carbocatalytic process reached up to 90% of the removal of pharmaceuticals in HWW. In turn, the Fe (II)+PMS+UVA process was able to degrade the target pharmaceutical by the action of both hydroxyl radical and sulfate radical, the process performance was improved by the addition of citric acid (resulting in a significant decrease of the treatment time). Furthermore, this photo-Fenton system led to removals between 30 and 90% of the pollutant in HWW. The economic calculations for the operation of the processes showed that carbocatalysis presented higher costs (11.057 USD m-3) than Fe (II)+PMS+UVA in presence of citric acid (4.92 USD m-3). The costs associated with the biochar preparation represented 82% of the value reported for the total operational cost in the carbocatalysis process. Meanwhile, the operational costs associated with the consumption of reagents represented ~ 99% of the value reported for the photo-Fenton process. The environmental impact analysis indicated that Fe (II)+PMS+UVA (with citric acid) process had a global warming potential of ~0.517 Kg CO2-Eq, which was six-fold lower than that for carbocatalysis (2.87 Kg CO2-Eq). The factor with the greatest environmental footprint for the carbocatalytic process was the biochar preparation, whereas in the Fe (II) +PMS + UVA processes, the reagents synthesis, and energy consumption were the factors with the main influence on the environmental impact. At the end, the processes comparison, considering the three criteria (technical, economic, and environmental) revealed that the Fe (II)+PMS+UVA in the presence of citric acid system was more suitable than carbocatalysis to remove the target pharmaceutical compounds in HWW. |
| Databáze: | OpenAIRE |
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