Productionof mesoporous activated carbon from cone of Iranian pine tree (Pinus eldarica) using chemical activation for adsorption of sodium dodecylbenzene sulfonate from aqueous solution

Recently pollution due to sewage containing surfactants has become a major cause of environmental pollution. Sodium dodecyl benzene sulfonate (SDBS) is one of the most important types of surfactants. The purpose of this study was to synthesize activated carbon (AC) from Iranian pine cones (Pinus eldarica) for the removal of sodium dodecylbenzene sulfonate (SDBS) from aqueous solution in batch systems.
The activated carbon samples were prepared using three activation agents including phosphoric acid, potassium carbonate and potassium hydroxide with different impregnation ratios. Pyrolysis process was performed in a ceramic furnace under a nitrogen gas flow rate of 100 ml/min with a heating rate of 8°C/min for 3 hours in 750 °C. Maximum surface area was obtained using synthesized activated carbon with H3PO4 in impregnation of 2:1 with 1580 m2/g. The synthesized activated carbon with three activating agents was used in the batch system to remove the SDBS from aqueous solution.
Findings: The results showed that activated carbon produced by potassium carbonate with impregnation ratio of 0.75:1 has the highest absorption capacity of 97.56 mg/g. The experimental kinetic data were analyzed by pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The result indicated that pseudo-second-order with R2>0.982 provided a better description of adsorption data. Desorption experiments were carried out using different compounds. Sulfuric acid and ethanol showed the highest desorption rates of 65/67 and 40/03%, respectively.