Thermo-kinetic investigation of heavy metal ions adsorption onto lignin considering coupled adsorption—desorption mechanisms: Modeling and experimental validation

摘要

A coupled adsorption—desorption thermo-kinetic model is developed incorporating both adsorption and desorption reactions. A local pseudo-equilibrium condition at the interface of adsorbent and adsorbate bulk phases was used as isotherm equation which can even be applied for multi-pollutants scenarios. The developed model is then validated using collected experimental data of heavy metal ions (Pb, Cu, Cd, Zn, and Ni). Comparisons were made for a number of isotherm and kinetic models to examine the performance of the proposed model. The developed model revealed desirable accuracy and superiority over other models in predicting the adsorption behavior and can be used for other systems of concern. The model correlates the adsorption kinetic with an R? value of 0.9391 and desorption kinetic with an R2 value of 0.9383. By application of the proposed model to any available adsorption datasets, the individual characteristics of adsorption and desorption can be determined. Wastewater; adsorption; desorption; thermo-kinetic modeling; isotherms