Lignin-derived hierarchical porous carbon with high surface area and interconnected pores for efficient antibiotics adsorption

Biomass-derived porous carbon is a promising antibiotic adsorption material due to its abundant reserves, low cost, and eco-friendly features. However, most biomass-derived porous carbon exhibits undesirable performance in the adsorption of high-molecular-weight antibiotics, which is attributed to the large mass transfer resistance during the adsorption process. Herein, we employ lignosulfonate (LS) as the biomass carbon source and CaCO3 as the activator to fabricate lignin-derived hierarchical porous carbon (LPC-CaCO3) which possesses a high surface area (2944 m2/g) and a large pore volume (1.406 cm3/g). Moreover, we demonstrate uniform mixing and simultaneous pyrolysis of carbon resources and activators are essential to the formation of interconnected pores. Large numbers of connected pores effectively reduce the mass transfer resistance. LPC-CaCO3 exhibits high adsorption capacity to low-molecular-weight antibiotics (sulfamethazine) and high-molecular-weight antibiotics (tylosin) in both batch and column modes. The adsorption performances of LPC-CaCO3 to antibiotics, especially high-molecular-weight antibiotics, are superior to most other reported biomass-derived carbons, commercial activated carbons, and petroleum-derived carbons. This work presents an effective strategy to fabricate a high-performance antibiotics adsorbent from biomass resources and provides deep insight into the structure–activity relationship of porous antibiotics adsorbents.