Efficient adsorption of typical antibiotics by petroleum coke-based ultra-large surface porous carbon materials: Mechanism and cost analysis

The misuse and residues of typical antibiotics cause serious threats to the aquatic environment, especially for non-biodegradable pollutants such as chloramphenicol (CAP) and norfloxacin (NOR). Currently, traditional adsorbents have limited effectiveness in treating this type of wastewater, and there is an urgent need to develop efficient and low-cost adsorbent materials balanced with green economy objectives. This study used petroleum coke, a common chemical waste, as a precursor to prepare ultra-large surface area porous carbon (UC) through multiple processes of “carbonization-oxidation-expansion-activation”. The adsorption characteristics and mechanisms were deeply analyzed by various characterization techniques, batch experiments, and classical adsorption models. The results showed that the specific surface area of UC was as high as 2569.43 m²·g⁻¹ with a multistage pore structure dominated by micropores. The theoretical maximum adsorption capacity of CAP and NOR by UC was 437.47 mg·g⁻¹ and 362.27 mg·g⁻¹, respectively. The adsorption is consistent with the Langmuir and Pseudo-second-order kinetic models. This adsorption mechanism is dominated by the single-molecule-layer physical interactions, mainly including surface adsorption and ion exchange, assisted by hydrogen bonding and π-π interactions. The full life cycle assessment of UC showed that its preparation cost is low, approximately 13.86 USD·kg⁻¹ (40.12 % of the raw material), and its performance was significantly better than that of the popular adsorbents. This work provides an economical and efficient technological approach for preparing high-performance adsorbents from petroleum coke resources, which is of great value for antibiotic wastewater treatment.