3.2.3. Computer simulation of breakthrough curve experiments

The concentration-time profiles of chlorogenic acid and caffeine at the exit end of the column, obtained from the adsorption-desorption experiments (breakthrough curves), were depicted using the mathematical models described in section 2.1. These models were utilized to tune-fit the experimental breakthrough curve data at various concentration levels in order to determine the adsorption parameters for each compound, including the linear adsorption isotherm constant, mass-transfer coefficient, and Péclet number. All equations were numerically solved using the finite element method in MATLAB® version 2021b and FLEXPDE® version 6.5, operating on the Windows® 10 operating system. The effectiveness of tune-fitting was evaluated by calculating the percentage average absolute relative deviation (%AARD) using Equation (27).