Continuous process for the effective removal of gasoline from an aqueous emulsion using mexicalcite as an adsorbent in a packed bed column

Abstract

Thanks to its extraordinary properties as an adsorbent, the mineral called “mexicalcite” was used to remove gasoline from a water emulsion in a continuous process. A glass column with an internal diameter of 1.6 cm was used to analyze the effect of the packed bed height (Z), flow rate (Q) and the influent concentration (C₀) on the percentage of gasoline removal (%R) and the adsorption capacity (q). The experimental results show that the effect of Z, Q, and C₀ is positive on the adsorption capacity, that is, an increase in the value of these three factors causes an increase in the amount of adsorbed gasoline. The only negative effect was found when the volumetric flow rate was modified; in this case, the percentage of gasoline removal decreased 8.7 and 15.4% when increased from 5 to 10 mL∙min^-1 and from 5 to 15 mL∙min^-1, respectively. Experimentally, the highest removal percentage (97.1%) and maximum adsorption capacity (132.23 mg∙g^-1) were obtained with a packed bed height of 4 cm, a volumetric flow rate of 5 mL∙min^-1 and an initial concentration of 1500 mg∙L^-1. The continuous process was successfully modeled using the Thomas, Adams-Bohart, Wolborska, Dose-Response, and Yoon-Nelson models. The Thomas and Dose-Response models yielded a maximum adsorption capacity of 125.31 mg∙g^-1. These results demonstrate that mexicalcite is a potential adsorbent for gasoline removal from water.

Keywords: adsorption capacity, gasoline removal, packed bed column, removal percentage, Thomas model.