Phenol removal via activated carbon from co-pyrolysis of waste coal tar pitch and vinasse

The behavior and characteristics of phenol adsorption by activated carbon produced from co-pyrolysis of coal tar pitch and vinasse were investigated. Coal tar pitch and vinasse (mass ratio of 1:3) were firstly co-pyrolyzed and carbonated at 400 °C for 2 h. The carbonized material produced was then soaked with saturated KOH solution and activated at 800 °C for 1 h to form activated carbon. Results from the phenol wastewater adsorption experiments suggest that pseudo-second-order kinetics and the Weber-Morris model could reflect the time-dependent adsorption behavior of phenol wastewater by the activated carbon, revealing that internal diffusion represents the rate-limiting procedure and dominant process to control the adsorption rate in the early stage of the adsorption. Monolayer adsorption played the key role during the phenol adsorption. The adsorption was an endothermic reaction in temperature ranging from 15 °C to 35 °C, indicating that the adsorption speed could be stimulated by the increasing temperature. This study establishes a theoretical foundation for the usage and the potential application of the activated carbon derived from coal tar pitch and vinasse in wastewater treatment.