Kinetic analysis of characteristics of an adsorption column for water purification based on AlOOH/MWCNTs/Ag composites

Abstract

Using the adsorption of eosin and methylene blue as examples, we performed a nonlinear kinetic analysis of their recovery on an AlOOH/MWCNTs/Ag composite sorbent in a fixed-bed column. Nonlinear regression analysis of experimental data was performed using the Thomas, Adams-Bohart, and Yoon-Nelson models. The values of the correlation coefficients R² indicate the applicability of these models in describing the experimental data. The following parameters were determined: dynamic capacity of the column, rate constant, time to release 50% of the sorbate depending on initial concentration, flow velocity, and layer height. The maximum sorption capacity based on the Thomas model was found to be 175.25 mg/g for eosin and 29.57 mg/g for methylene blue. The Adams-Bohard model predicted the maximum sorption capacity of the column to be 781.5 mg/L for eosin and 128.21 mg/L for methylene blue. According to the Yoona-Nelson model, the estimated time to reach half the concentration of eosin in the filtrate from the initial value is 418.91 min and 142.38 min for methylene blue. The results confirm that the AlOOH/MWCNTs/Ag composite can be used to remove organic dyes from water under dynamic conditions.