Quantum chemical calculations and molecular modeling for methylene blue removal from water by a lignin-chitosan blend.

A comprehensive analysis of the molecular dynamics and quantum chemical calculation methods for methylene blue removal by adsorption were carried out. The experimentally measured adsorption data of methylene blue from water effluent on a novel lignin and chitosan blend were used to validate the modeling results. The method and required steps for application of quantum chemical calculations and molecular modeling techniques as the state of the art approach for predictive modeling and investigation of adsorption were provided, and the model findings were validated by comparing with the experimental data; close agreement between the results was observed. The conductor-like screening model (COSMO) approach was used for calculation of equilibrium concentration of solute at the adsorbent-solute interface. The results revealed that the approach is highly recommended as it provides an alternative assessment for feasibility analysis before any experiments to be undertaken, resulting in time and cost saving.