Low-cost adsorbent prepared from poplar sawdust for removal of disperse orange 30 dye from aqueous solutions

In this study, the applicability of char generated from poplar sawdust as an inexpensive adsorbent for the removal of a textile dye is investigated. Adsorbent samples were generated through pyrolysis at temperatures of 500, 600, 700 and 800 °C. The structural features of the char samples were illuminated by elemental analyses, FTIR, BET and SEM analyses. The effect of operating parameters such as initial dye concentration, pH and temperature were investigated and optimal values extracted. The adsorbent generated at 800 °C showed maximum adsorption efficiency of 83.4% at operating condition of pH 2, initial dye concentration of 50 ppm and temperature of 67 °C. We experimentally obtained equilibrium isotherms for the adsorption of the dye. The results were modeled using Langmuir, Freundlich and the Redlich–Peterson equations with corresponding parameters being determined. The mechanism was better represented by the Redlich–Peterson isotherm.