production of effective activated carbon from scotch pine bark and investigation of the adsorption properties

In this study, the bark of scotch pine, a common tree species that can easily grow in different weather conditions, was chosen as a biomass source. firstly, bio-carbon (bc) was produced by hydrothermal pretreatment from the milled and sieved scotch pine bark (spb). then, the final activated carbon (ac) was obtained from the bc by chemical activation (kcl and na2s2o3). the produced samples were characterized by sem, ft-ir, bet, and phzpc analyses. the adsorption studies of samples were carried out over the removal of methylene blue (mb). the optimum conditions were determined for the parameters of ph (8), temperature (25°c), dye concentration (200 mg/l), adsorbent amount (0.08 g), and contact time (60 min). the langmuir was determined as the fittest model with the highest r2 value (≈0.9988) with nonlinear regression in the isotherm studies. in addition, the max adsorption capacity and the surface area were found to be 374.183 mg/g and 1258.25 m2/g, respectively. in the kinetic studies, the pseudo-second-order model was determined as the most suitable model with the highest r2 value (≈0,9999) by the nonlinear regression method. it was also determined by the calculated activation energy that the adsorption is a physical sorption process. as a result, it was found that the modified ac obtained from the spb biomass is a highly effective adsorbent in the removal of mb.