THE HIGH-EFFICIENCY CR(VI) ADSORPTION USING POPLAR WOOD BASED ACTIVATED CARBON

Activated carbons were obtained from poplar sawdust with H3PO4 activation in this study. Activated carbons were produced as 2:1 (PL2-400), 3:1 (PL3-400), and 4:1 (PL4-400) by mass chemical substance/chip ratio at 400 °C carbonization temperature with an impregnation process. These activated carbons' surfaces were identified by BET, SEM-EDX, and FTIR analyses. Cr(VI) heavy metal adsorption was carried with activated carbon (PL4-400, 1345.26 m2/g), which has the highest surface area. Adsorption was carried out at the 2-9 pH range, in the range of 0.001-0.1 g activated carbon, and at temperatures of 25, 35, and 45 °C. The Kinetics of Cr(VI) adsorption was characterized by using adsorption kinetic models. The relationship between adsorbent and adsorbed is explained by Langmuir and Freundlich isotherm models. It was observed that the Cr(VI) adsorption on PL4-400 was more compatible with the Langmuir adsorption model. In addition, ΔG°, ΔS°, and ΔH° values were determined by making thermodynamic calculations, and the applicability of the adsorption was identified as endothermic and spontaneous.