Preparation and selection of low-cost biomaterials for the quaternary treatment of wastewater effluent for pharmaceutical removal

The presence of pharmaceuticals in wastewater effluents constitutes a significant public health concern, primarily due to their unknown cocktail effects on human health and their role in promoting antimicrobial resistance, thereby compromising the efficacy of therapeutic interventions. Furthermore, these emerging contaminants have harmful effects on aquatic ecosystems, causing disorders in the reproduction, behaviour and survival of resident wildlife. Conventional wastewater treatment technologies are largely ineffective at achieving efficient removal of such contaminants, resulting in their continuous release and persistent ecological disruption. Consequently, and in line with recent updates to European legislation, the development and optimisation of advanced, efficient removal strategies are critical. In this work, sixteen activated carbon biomaterials were synthesised, characterised, and systematically assessed for their removal efficiency toward diclofenac (DCF), valsartan (VAL), and iopromide (IOP), with their performance benchmarked against NORIT (the commercial activated carbon used as a reference). The top-performing biomaterial produced from Juncus maritimus biomass was subsequently selected for further adsorption tests, including evaluation in both a controlled synthetic aqueous matrix and a real wastewater effluent containing a mixture of the target pharmaceuticals. Further kinetic and equilibrium isotherm analyses were performed to elucidate the underlying adsorption mechanisms. The results indicate that the adsorption performance of the selected material is not adversely affected by the compositional complexity of the real wastewater matrix. Notably, this study presents the first evidence of a biomaterial capable of selectively removing specific pharmaceutical contaminants without appreciable competition for active sites under real effluent conditions.