Browsing by Author "Saez-Navarrete, C."

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    Anaerobic biodegradability of leachate from MSW intermediate landfill
    (2019) Baraza, X.; Saez-Navarrete, C.; Torres-Castillo, R.
    Anaerobic digestion has been used for decades to treat leachate from municipal solid waste landfills. Due to the characteristics of this kind of effluent, the biodegradability results have not been as satisfactory as could be hoped. Consequently, this area has long been a focus of study. This paper contributes to knowledge of the characteristics of biodegradability of this kind of waste effluent, through application to a real case. Biodegradation performance was studied in depth using a range of physicochemical parameters and the amount of methane produced by various volumetric ratios of substrate: inoculum between 2: 50 and 50: 50 at 35 degrees C and atmospheric pressure by using anaerobic batch tests in 500 mL bottles. It has been observed an optimal situation for the ratios between 16: 50 and 24: 50 ratios with values of biodegradability COT 45% and 35% in COD. For smaller proportions it has detected the completion of the lack of readily biodegradable substrate. For higher proportions it is considered that the ammoniacal nitrogen has had an inhibiting effect on the anaerobic process.
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    Novel photobioreactor design for the culture of Dunaliella tertiolecta - Impact of color in the growth of microalgae
    (2019) Rebolledo-Oyarce, J.; Mejía López, José Félix; García Alimenti, Griselda Noemi; Rodríguez Córdova, Leonardo A.; Saez-Navarrete, C.
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    Role of biosolids on hydrophobic properties of sulfide ores
    (2011) Reyes-Bozo, L.; Herrera-Urbina, R.; Escudey, M.; Godoy-Faundez, A.; Saez-Navarrete, C.; Herrera, M.; Ginocchio, R.
    The effect of biosolids on hydrophobic properties of sulfides ores was studied. The principal components of biosolids are humic substances, mainly humic acid, and phosphorus compounds. The feasibility of using biosolids as collector for copper sulfide ores (CSO) was performed through zetapotential measurements, FT-IR analysis and film flotation tests. Addition of different dosages of biosolids, a commercial humic acid (CHA), and an industrial collector makes the zeta potential of a copper sulfide ore more electronegative in the entire pH range studied. FT-IR spectra show that CHA can interact with mineral surfaces through outer-sphere linkages. CHA can adsorb physically on chalcopyrite and pyrite through hydrogen bonds or Van der Waals forces. Orthophosphate, however, adsorbs chemically on the surfaces of these mineralogical species through inner-sphere linkages. Therefore, biosolids that contains both humic acid and phosphorus compounds can interact with CSO surfaces through a complex mechanism involving both inner and outer-sphere linkages. Further, film flotation tests - in accordance with zeta potential results - show that biosolids adsorb on the surface of the sulfide ores investigated, changing their hydrophobicity. Biosolids show greater affinity for pyrite while commercial humic acid show similar behavior to industrial collectors. Therefore, both biosolids and humic acids can change the hydrophobic properties of sulfide ores and can be used as collectors in froth flotation processes. Further research will be needed in order to scale-up laboratory results to industrial mineral operations. (C) 2011 Elsevier B.V. All rights reserved.