TiO2 and activated carbon of Argania Spinosa tree nutshells composites for the adsorption photocatalysis removal of pharmaceuticals from aqueous solution

This work demonstrates the interest of new bio composite materials for the elimination of pharmaceuticals (diclofenac (DCF), carbamazepine (CBZ) and sulfamethoxazole (SMX)) from aqueous solution. The synthesized materials are based on activated carbon (ACP) of Argania Spinosa tree nutshells by calcination and H3PO4 activation, and commercial TiO2 (Degussa P25). AC/TiO2 composite materials were prepared by temperature impregnation with different TiO2 mass ratio (9, 16.6 and 33.3%). Characterization of AC and AC/TiO2 revealed remarkable adsorption properties of bio sourced AC (BET surface area of 1159 m2/g) and successful deposition of layer of TiO2 on AC surface in controlled amount, with some physical changes (surface area and total pore volume decrease). Langmuir model describes efficiently adsorption of pharmaceuticals onto AC/TiO2 with maximum capacities of 153.8, 105.3 and 125.0 mg/g at 25 °C with 9% of TiO2 (AC/TiO2-9%) for DCF, CBZ and SMX, respectively. Photocatalytic activities of all composites were validated on CBZ. The elimination efficiency of relative high concentration of pharmaceuticals (50 mg/L) were proved with disappearances in the range of 50–100% after six hours upon simulated solar irradiation with the most interesting material AC/TiO2-9% at a concentration of 0.1 g/L.