Microporous carbon derived from waste plastics for efficient adsorption of tetracycline: Adsorption mechanism and application potentials

In recent years, the accumulation of waste plastics and emergence plastic-derived pollutants such as microplastics have driven significantly the development and updating of waste plastic utilization technology. This study prepared the porous carbon (PC-1-KOH) material directly from polyethylene terephthalate (PET) in waste plastic bottles using KOH activation and molten salt strategy for efficient removal of antibiotic tetracycline (TC). The maximum removal efficiency of TC was 100.0% with a PC-1-KOH weight of 20 mg. In addition, the TC removal efficiency stayed over 80.0% within the rage of pH of 3–9 and different water bodies. The adsorption process was described by the Pseudo-second-order kinetic model and the Langmuir isotherm, suggesting that the adsorption of TC was predominantly chemical in nature and occurred on a homogeneous surface. The pores filling, hydrogen bonding, π-π stacking interactions and electrostatic interaction are the main mechanisms of TC adsorption. This work demonstrates a sustainable approach to converting plastic waste derived materials into functional materials for effective pollution removal and environmental remediation.