Abstract:
In order to address the threat of antibiotic contamination in the aquatic environment to the ecosystem and human health, as well as to promote the high-value utilization of heavy bio-oil, the present study is dedicated to the development of a porous carbon material with high adsorption capacity and high stability. Aiming at the problems of single pore structure and insufficient surface active sites of traditional biochar adsorbents, the synergistic strategy of metal-organic skeleton template method and chemical activation was combined. By regulating the carbonation process of the heavy components of bio-oil, the adsorption mechanism of tetracycline was explored to provide theoretical support for the large-scale application of green adsorbent materials. In this study, porous carbon materials were prepared by using the heavy fraction of bio-oil as a renewable carbon source, and by synchronously integrating the 2-methylimidazole zinc salt and the KOH activator through the one-pot method to achieve the synergistic effect of template-directed pore-making and chemical activation during the high-temperature carbonization process. In order to reveal the synergistic mechanism, three types of materials containing only template (HZ-800), only activator (HK-800) and both synergistically (HZK-800) were prepared in comparison. The system adopted specific surface area analysis and micro-morphological characterization to analyze the structural properties of the materials, investigated the influence of environmental conditions on the removal efficiency of tetracycline through a series of adsorption experiments, and elucidated the adsorption mechanism by combining kinetic modelling, isotherm fitting and thermodynamic parameter calculations. The results showed that the synergistic effect of the template and activator effectively constructed a hierarchical pore network, and HZK-800 exhibited a significantly optimized specific surface area and good pore structure, and its adsorption performance far exceeded that of a single treated material. The maximum adsorption capacity of this material for tetracycline reached 464.55 mg/g, and the adsorption efficiency remained stable in strong acid and alkali environments. Structural characterization confirmed that template-guided formation of mesoporous frameworks, activator etching to generate abundant micro-pores, and carbonation of aromatic components of bio-oil to form highly stable graphitized materials synergistically achieved the modulation of pore structure and surface chemistry. HZK-800 porous carbon showed significant advantages in adsorption capacity, environmental adaptability and cyclic stability. It provided an economical and efficient solution for antibiotic pollution treatment, as well as a new idea for the efficient transformation of biomass resources and the design of functionalized carbon materials, which was of practical significance in promoting the green development of water treatment adsorption technology.