Evaluation of a Biobased Activated Carbon for the Removal of Two Representative Pharmaceuticals from Urban Wastewater Effluents: Assessing Matrix and Multi-Component Effects

Adsorption on activated carbon (AC) can be used in the wastewater sector to improve treated effluent quality. This study evaluates the performance of a biobased AC relative to that of a coal-based AC, which is more widely used industrially despite its higher environmental impact. These adsorption performances are influenced by both the complexity of the water matrix and the physicochemical characteristics of AC. For these reasons, the adsorption of two representative pharmaceuticals (carbamazepine and sulfamethoxazole) in three different matrices, deionized water (DW), synthetic water with ions (SW), and wastewater secondary effluents (SEs), by two ACs (from wood and from coal), was investigated. The effects of the matrix and competition adsorption between both pharmaceuticals were studied. Adsorption kinetics and isotherms in the three matrices and breakthrough curves in a fixed-bed study were performed. Complexification of the matrix leads to a decrease in adsorption, especially in SE, where dissolved organic matter inhibits the adsorption rate and diffusion of the pharmaceuticals. Competition between pharmaceuticals was observed in SW in batch and fixed-bed studies, and showed that CBZ adsorption is favored over SMX because of the higher affinity of CBZ. Performances of biobased AC are slightly lower, but remain promising for a sustainable treatment process.