Optimization of the preparation of activated carbon from steam activated cornstraw black liquor for phenol removal

The activated carbon (AC) was produced from steam activation of cornstraw black liquor. Response surface methodology (RSM) and the central composite design (CCD) were employed for determining optimal adsorbents with maximum phenol removal capacity. The operational parameters such as activation temperature (°C), duration (min) and steam velocity (SV) (L min⁻¹) were chosen as independent variables in CCD. The statistical analysis indicates that the effects of activation temperature, duration, steam flow rate and combined effect of activation temperature and duration are all significant to the phenol removal capacity. The optimal condition for achieving the maximum phenol adsorption capacity is obtained as the followings: carbonization temperature (850 °C), duration (2.1 h) and SV (38 L h⁻¹) with phenol removal capacity reaching 130 mg/g. The BET specific surface area of AC prepared at optimal conditions could reach 800 m²/g.