Activated char embedded in biodegradable film for antimicrobials removal: Towards sustainable water purification

The development of sustainable materials toward efficient pollutant removal is crucial for water remediation. Following a waste-to-wealth approach, we report a novel preparation of biodegradable film embedded with a biomass-derived activated char and its effective application for the removal of fluoroquinolones from aqueous solutions. The presence of these antimicrobials contributes to the worrying increase of environmental antimicrobial resistance and ecotoxicity since they are emerging and harmful pollutants, and requires effective solution for their removal. The impact of different parameters on the sorptive performance was evaluated (e.g., type of polymeric support and char, amount of char), revealing that the removal process strongly depends on the type and amount of activated char used, whereas the polycaprolactone only acts as a support immobilizing the char and facilitating the sample treatment. By simply suspending the film in the aqueous sample, it is possible to adsorb the target contaminants, with removal efficiency up to 80 % in 240 min and satisfactory cumulative sorption capacity (Q up to 14,000 μg g⁻¹) in competitive conditions. The sorption process obeys second-order kinetics in all the water samples tested (potable water, river water and wastewater). Notably, the film demonstrated continued stable removal capabilities over multiple uses (up to five). This work provides a new strategy for exploring a novel and efficient film for water purification.