Conversion of Erythrina speciosa pods to porous adsorbent for Ibuprofen removal

The seed pods of the forest species Erythrina speciosa were pyrolyzed with ZnCl2 to obtain porous activated carbon (Ery-AC) for adsorption purposes of Ibuprofen. The new material was microporous with a surface area of 795 m2 g-1. The kinetic and isothermal studies were conducted at a pH of 3 and an Ery-AC dosage of 0.75 g L-1. The Freundlich and Langmuir isotherms fitted the equilibrium curves, being the adsorption capacity of 98.11 mg g-1. Studies confirmed the endothermic nature (ΔH0 =27.36 kJ mol-1). System equilibrium was reached at around 100 min. The linear driving force (LDF) model fits the data satisfactorily. Besides, Ery-AC was tested on a simulated effluent containing various pharmaceutical compounds, presenting a removal efficiency of 65.54 %. The new activated carbon was tested to remove Ibuprofen from water in concentrations of μg L-1 and presented excellent results (95 % of removal). Last, regeneration revealed that the Ery-AC could be used 7 times. Therefore, applying seed pods of the forest species Erythrina speciosa carbonized with ZnCl2 is highly efficient in removing Ibuprofen and mixtures with other pharmaceuticals.