RESUMEN
Effective management and remediation strategies are crucial to minimize the impacts of both organic and inorganic contaminants on environmental quality and human health. This study investigates a novel approach utilizing cotton shell activated carbon (CSAC), rice husk activated carbon (RHAC), and wasp hive activated carbon (WHAC), produced through alkali treatment and carbonization under N2 atmosphere at 600 °C. The adsorption capacities of biomass-derived mesoporous activated carbons (CSAC, RHAC, WHAC) alongside macroporous commercial activated carbons (CAC) were evaluated for removing rhodamine B (Rh B) and hexavalent chromium (Cr6+). The CSAC exhibits remarkable adsorption efficiency (255.4 mg.g-1) for Cr(VI) removal, while RHAC demonstrates superior efficacy (174.2 mg.g-1) for Rh B adsorption. Investigating various optimal parameters including initial pH (pH 3 for Cr and pH 7 for Rh B), catalyst dosage (200 mg.L-1), and initial concentration (20 mg.L-1), the Redlich-Peterson isotherm model is applied to reveal a hybrid adsorption mechanism encompassing monolayer (chemisorption) and multilayer (van der Waals adsorption) processes. Kinetic analysis highlights the pseudo-second-order and Elovich models as the most suitable, suggesting physiochemisorption mechanisms. Thermodynamic analysis indicates the endothermic nature of the adsorption process, with increased randomness at the solid-solution interface. Isosteric heat investigations using Clausius-Clapeyron, Arrhenius, and Eyring equations reveal a heterogeneous surface nature across all activated carbons. Further confirmation of Rh B and Cr(VI) adsorption onto activated carbons is provided through FTIR, FESEM, and EDAX analysis. This study highlights the innovation and promise of utilizing biomass-derived activated carbons for effective pollutant removal.
RESUMEN
Calotropis gigantea essential oil is utilized in outmoded medicine, therapeutics, and the cosmetic industries. However, the extreme volatility, oxidation susceptibility, and instability of this oil restricts its application. Thus, encapsulation is a more effective method of shielding this oil from unfavorable circumstances. The creation of oil/water (O/W) nanoemulsions based on Calotropis gigantea essential oil (CEO), known as CNE (Calotropis gigantea essential oil nanoemulsions), and an assessment of its biological potential were the goals of this work. UV, fluorescence, and FT-IR methods were used for physiological characterization. Biological activities, including anti-inflammatory, anti-diabetic, and anti-cancer effects. Studies on the pharmacokinetics of CNE were conducted. CNEs encapsulation efficiency was found to be 92%. The CNE nanoemulsions had a spherical shape with polydispersity index of 0.531, size of 200 nm, and a zeta potential of -35.9 mV. Even after being stored at various temperatures for 50 days, CNE nanoemulsions remained stable. Numerous tests were used to determine the antioxidant capacity of CNE, and the following IC50 values (µl/mL) were found: iron chelating assay: 18, hydroxyl radical scavenging: 37, and nitric oxide radical scavenging activity: 58. The percentage of HeLa cells that remained viable after being treated with CNE was 41% at a higher dose of 1 µl. CNE inhibited α-amylase in a dose-dependent manner, with 72% inhibition at its higher dose of 250 µL. Research on the kinetics of drugs showed that nanoemulsions showed Higuchi pattern. This research showed potential use of Calotropis gigantea oil-based nanoemulsions in the food, cosmetic, and pharmaceutical industries.