Preparation of Chladophora‐Based Biochar and Its Adsorption Properties for Antibiotics

Abstract The biochar prepared by Chladophora (CB) was used to adsorb the ibuprofen and ofloxacin in sewage. SEM showed that CB preserved the natural tubular structure and increased its specific surface area. According to the BET results, the specific surface area of CB was 296.831 m 2 g ‐1 . The adsorption of ibuprofen and ofloxacin on biochar conformed to the pseudo second‐order kinetic model, indicating that their adsorption rate was controlled by the chemical adsorption mechanism. According to the adsorption isotherms study, the adsorption of ibuprofen on CB met the Dubin‐Radushkevich model, while it fitted well with the Freundlich model for ofloxacin adsorption, making their adsorption onto biochar relating to non‐uniform surface and adsorption layer, respectively. The pore filling and electrostatic interaction were considered the main mechanism for the adsorption of pharmaceuticals and personal care products on CB, whereas the π‐π electron donor acceptor (EDA) interaction and hydrogen bond would also partially contribute to the adsorption process.