Kinetic studies on the potential use of citrus-based green and low-cost demulsifying agents for the oil-in-water emulsions' treatment.

Water and oil form stable emulsions that are difficult to separate without the proper resources. In this study, the performance of green and low-cost demulsification agents was assessed, and the influences of the operating parameters on the performance of the demulsification process were evaluated. The main objective was to examine the kinetics of each demulsification formula and the dehydration efficiency as a function of time. Citrus fruits, namely Citrus aurantifolia (lime) and Citrus limon (lemon), and ready to consume Citrus sinensis (orange) fruit juice was studied. Moreover, the rate constants (k), coefficient correlation (R²), and the dehydration efficiencies (∅(t)) were analyzed for each PFO model. The first-order models could satisfactorily represent the experimental data for the orange, lime, and lemon demulsification agents. The lemon demulsification formulation worked best at a temperature of 80 °C. The optimal pH value for the formula was 5. The overall fit of the experimental data to the PFO model was satisfactory for the temperatures 60 °C, 70 °C, and 80 °C. However, variations in the pH of the treated solutions did not yield good first-order fits, presumably due to a change in the mechanism of demulsification. [Display omitted] • Low-cost demulsifying agent an effective method for oil-contaminated water remediation. • Experimental data fitted to pseudo-first-order kinetic model (PFO) model. • The best results for each demulsification formula were produced at 80 ℃. • Demulsification agents performed best at a pH of 5. • Best demulsification was obtained in Lemon for its high citric acid content (48 g/L). [ABSTRACT FROM AUTHOR]