Browsing by Author "Pizarro, Guadalupe"

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    Nano-composites based on ligno-sulfonate and titanium oxide to study methylene blue removal and photo-degradation
    (2024) Boulett, Andres; Roa, Karina; Pizarro, Guadalupe; Sanchez, Julio
    The dyes in minimum concentrations are toxic, cause visual and photosynthetic contamination in natural waters. For this reason, in this study, methylene blue (MB) adsorbent nano-composites were prepared based on variable percentages of sodium ligno-sulfonate (LS) (0.00-30.0 wt%) and titanium oxide nanoparticles (Np TiO2) (0.00-10.0 wt%) in sodium poly (4-styrene sulfonate) (P(SSNa)). Chemical, morphological, and thermal techniques corroborated the presence of the main functional groups of the nano-composites, with surfaces formed by macro-pores, and that of Np TiO2 showed an increase in the thermal stability of the material. On the other hand, from studies of hydration of the nano-composites, percentages higher than 4000% were obtained with low dependence on pH effects, which could benefit the diffusion of the pollutant to the adsorbent in its adsorption. In relation to this, the MB retention capacity was evaluated by experimental parameters, such as % LS, % Np TiO2, pH, presence of ionic strength, contact time, MB concentration and amount of nano-composites. A maximum MB adsorption efficiency of 94.8 % and a capacity of 2886 mg g- 1 were obtained using the P(SSNa)-based system with 20% LS and 10% Np TiO2. The obtained results were fitted to the pseudo-second order kinetic model and Langmuir and Redlich-Peterson isotherm models. In addition, through the synergistic effect of adsorption and photo-degradation, 97.5% of the MB was removed within 1 h of irradiation.
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    Sodium lignosulfonate as an extracting agent of methylene blue dye using a polymer-enhanced ultrafiltration technique
    (2024) Sotelo, Sebastian; Oyarce, Estefania; Roa, Karina; Boulett, Andres; Pizarro, Guadalupe; Sanchez, Julio
    The purpose of this research was to evaluate the efficacy of sodium lignosulfonate (LS) as a dye adsorbent in the removal of methylene blue (MB) from water by polymer-enhanced ultrafiltration. Various parameters were evaluated, such as membrane molecular weight cut-off, pH, LS dose, MB concentration, applied pressure, and the effect of interfering ions. The results showed that the use of LS generated a significant increase in MB removal, reaching an elimination of up to 98.0 % with 50.0 mg LS and 100 mg L-1 MB. The maximum MB removal capacity was 21 g g-1 using the enrichment method. In addition, LS was reusable for up to four consecutive cycles of dye removal-elution. The removal test in a simulated liquid industrial waste from the textile industry was also effective, with a MB removal of 97.2 %. These findings indicate that LS is highly effective in removing high concentrations of MB dye, suggesting new prospects for its application in water treatment processes.