Efficient adsorption removal of carbamazepine from water by dual-activator modified hydrochar

The decontamination of trace micropollutants from water environments is a widely concerned issue, and developing green and efficient adsorbent serves as an effective solution. In this study, using dual-activator modification method, an efficient hydrochar adsorbent was prepared through a two-step sequential process combining H 3 PO 4 hydrothermal treatment with K 2 CO 3 pyrolysis activation for carbamazepine (CBZ) adsorption removal. The results indicated that H 3 PO 4 facilitated the K 2 CO 3 activation process. The prepared hydrochar exhibited excellent adsorption properties due to its high specific surface area (1265.08 m 2 ·g −1 ) and aromatic porous mesh structure, with the maximum and dynamic adsorption capacity for CBZ of 376.11 and 296.98 mg·g −1 , respectively. The adsorption mechanism primarily involved pore-filling effects, π-π electron-donor–acceptor (EDA) interactions and hydrophobic interactions. Additionally, the obtained hydrochar material showed high adsorption efficiency for various pollutants and performed well in actual water samples. This study may provide theoretical and technical support for the development and application of high-efficiency hydrochar-based adsorbents.