Effect of calcination temperature of sawdust as a sorbent for bromo phenol red removal from aqueous solutions

Sawdust (SD) was calcinated at different temperatures (100°C–1,000°C). SDs were characterized by FTIR and SEM. SEM image showed spherical and uniformed shapes with particle sizes of 50 and 35 nm for SD calcinated at 600°C and 1,000°C, respectively. The adsorption of bromophenol red (BPR) by SDs was studied. The optimum conditions for the maximum removal of BPR were found at pH > 6, contact time 60 min and adsorbent dose of 0.1 g. The sequence capabilities of SD calcinated at different temperatures for adsorption of BPR were as follows: SD1,000 > SD800 > SD600 > SD400 > SD200 > SD100. Two common kinetic models, Lagergren’s pseudo-first-order and pseudo-second-order models were employed to describe the adsorption kinetics. Adsorption of BPR was followed by pseudo-second-order kinetic model. Equilibrium data were analyzed by Freundlich and Langmuir isotherms. The best fit to the data for adsorption of BPR was obtained with the Langmuir isotherm. Thermodynamic results showed the endothermic and spontaneous process. The spent SD was regenerated through simple physical method.