Rapid methylene blue adsorption using modified lignocellulosic materials

Lignocellulosic matter was grafted with neem oil-phenolic resin for developing a highly efficient adsorbent capable of capturing dye rapidly from water. Methylene blue was used for demonstrating the removal efficacy of the treated lignocellulosic biomatters. Effect of adsorbent dose, pH, time and temperature on removal efficiency was investigated. The data indicate that after modification, methylene blue removal efficacy of lignocellulosic matter increased from 455 mg/g to 2000 mg/g. The removal efficiency of the treated biomatters was unaffected for the pH range between 2 and 8. The treated biomatters rapidly captured above 95% of the initial methylene blue content from water within 5 min. The kinetic and thermodynamic study indicated that MB removal was pseudo second order endothermic process. The chemical characterization indicated that MB was captured on the surface of the biomatters through electrostatic interaction, hydrogen bonding and van der Waals forces. The study also indicated that the materials could be regenerated and reused for more than five cycles with slight decrease of the removal efficiency. This treated lignocellulosic biomatters based process was found to be comparable or better than their available alternatives. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.