| Summary: | Biobased carbon materials (BBC) obtained from Norway spruce (Picea abies Karst.) bark was produced by single-step chemical activation with ZnCl<sub>2</sub> or KOH, and pyrolysis at 800 °C for one hour. The chemical activation reagent had a significant impact on the properties of the BBCs. KOH-biobased carbon material (KOH-BBC) had a higher specific surface area (S<sub>BET</sub>), equal to 1067 m<sup>2</sup> g<sup>−1</sup>, larger pore volume (0.558 cm<sup>3</sup> g<sup>−1</sup>), more mesopores, and a more hydrophilic surface than ZnCl<sub>2</sub>-BBC. However, the carbon yield for KOH-BBC was 63% lower than for ZnCl<sub>2</sub>-BBC. Batch adsorption experiments were performed to evaluate the ability of the two BBCs to remove two dyes, reactive orange 16 (RO-16) and reactive blue 4 (RB-4), and treat synthetic effluents. The general order model was most suitable for modeling the adsorption kinetics of both dyes and BBCs. The equilibrium parameters at 22 °C were calculated using the Liu model. Upon adsorption of RO-16, Q<sub>max</sub> was 90.1 mg g<sup>−1</sup> for ZnCl<sub>2</sub>-BBC and 354.8 mg g<sup>−1</sup> for KOH-BBC. With RB-4, Qmax was 332.9 mg g<sup>−1</sup> for ZnCl<sub>2</sub>-BBC and 582.5 mg g<sup>−1</sup> for KOH-BBC. Based on characterization and experimental data, it was suggested that electrostatic interactions and hydrogen bonds between BBCs and RO-16 and RB-4 dyes played the most crucial role in the adsorption process. The biobased carbon materials showed high efficiency for removing RO-16 and RB-4, comparable to the best examples from the literature. Additionally, both the KOH- and ZnCl<sub>2</sub>-BBC showed a high ability to purify two synthetic effluents, but the KOH-BBC was superior.
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