Preparation and evaluation of poplar waste derived adsorbent for dye removal

Poplar waste is employed to prepare the high quality adsorbent (PWA) using one-pot method for methylene blue (MB) removal from wastewater. The H2 rich fuel gas is recycled during preparation process. The adsorption isotherms and adsorption kinetics are used to describe the MB adsorption process. The MB adsorption capacity of the PWA is 254.21 mg/g based on the Langmuir model calculation. Pseudo-second-order model describe well with the adsorption kinetic process. The MB column adsorption process of the PWA is analyzed by the Thomas and Yoon-Nelson, which indicates that the adsorption capacity is 54 mg/g and saturation time is 540 min. PWA has excellent reusability, which still maintains 75.59% MB adsorption amount after five cycles. The MB adsorption mechanism of PWA includes chemical functional groups, electrostatic interaction and pore filling. Density functional theory calculation indicates that hydroxyl groups play an important role in MB adsorption process. MB adsorption performance of PWA is investigated in the actual water with excellent MB removal. This result demonstrates that PWA could be acted as the recoverability and efficient adsorbent for MB removal from wastewater.