A charcoal was produced from primary pulp mill sludge and then used for the adsorptive removal of diclofenac, salicylic acid, ibuprofen and acetaminophen. A main aim was to assess the utilization of this material for the tertiary treatment of sewage. For this purpose, the adsorption of the selected pharmaceuticals from the secondary effluent of a sewage treatment plant (STP) was compared with their adsorption from ultrapure water. Differences in the adsorption kinetics and equilibrium were evident between the four pharmaceuticals considered. However, differences between the adsorption from the two aqueous matrixes considered were negligible. It was hypothesized that synergetic microorganism removal compensated the competitive effects in wastewater

In view of the valorisation of the green microalga Scenedesmus obliquus biomass, it was used for the biosorption of two nonsteroidal anti-inflammatory drugs, namely salicylic acid and ibuprofen, from water. Microalgae biomass was characterized, namely by the determination of the point of zero charge (pH_PZC), by Fourier transform infrared (FT-IR) analysis, simultaneous thermal analysis (STA) and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Kinetic and equilibrium batch experiments were carried out and results were found to fit the pseudo-second order equation and the Langmuir isotherm model, respectively. The Langmuir maximum capacity determined for salicylic acid (63 mg g⁻¹) was larger than for ibuprofen (12 mg g⁻¹), which was also verified for a commercial activated carbon used as reference (with capacities of 250 and 147 mg g⁻¹, respectively). For both pharmaceuticals, the determination of thermodynamic parameters allowed us to infer that adsorption onto microalgae biomass was spontaneous, favourable and exothermic. Furthermore, based on the biomass characterization after adsorption and energy associated with the process, it was deduced that the removal of salicylic acid and ibuprofen by Scenedesmus obliquus biomass occurred by physical interaction.