Production of char from hornbeam sawdust and its performance evaluation in the dye removal

Hornbeam sawdust was used as a biomass sample in the experiments involving char production. Within this purpose, a slow pyrolysis of the biomass sample was carried out in a fixed-bed reactor. The chemical characteristics of the chars obtained at 500, 600, 700 and 800 °C were identified by FTIR, BET and SEM analyses. The results of the analyses indicate that the properties of char greatly depend on the pyrolysis temperature. The higher the temperatures reached, the greater the amount of porous material obtained.In the second part of the study, four chars obtained through pyrolysis of hornbeam sawdust at different temperatures were used as an adsorbent for the removal of disperse orange 30 (DO30). Batch studies were performed to address various experimental parameters, such as pH, adsorbent dose, initial dye concentration, temperature and contact time for the removal of DO30. Dye was removed with the highest ratio decreasing both pH and the initial dye concentration. An increase in the amount of adsorbent, temperature and contact time also increased the dye removal efficiency. The greatest dye removal efficiency among the tested parameters was 71%. This was achieved using the 800 °C char at a concentration of 2.4 g L−1 and a solution pH of 2.

► Chars were produced from hornbeam sawdust by slow pyrolysis. ► The chemical characteristics of the chars obtained were identified by FTIR, BET and SEM analyses. ► Obtained chars were used as an adsorbent for the removal of disperse orange 30. ► The maximum dye removal efficiency (71%) was achieved using optimum parameters.