Efficient removal of tetracycline and Cu by honeycomb derived magnetic carbon: Adsorption mechanism and advanced oxidation regeneration mechanism.

The honeycomb magnetic carbons (xFe@HCNs) were prepared by sacrificial template method novelty using polyacrylamide resin (PAAS) as template and ammonium pyrrolidine dithioate/Fe complex (APDC-Fe) as carbon skeleton and metal source. Tetracycline (TC) and copper (Cu) as target pollutants were used to investigate the adsorption properties of xFe@HCNs in single or binary TC and Cu systems. The adsorption capacity sequence for TC among the adsorbents was (mmol·g): 2Fe@HCNs (0.088) > 8Fe@HCNs (0.061) > HCNs (0.054) > RC (0.036), and for Cu was (mmol·g): 2Fe@HCNs (1.120) > 8Fe@HCNs (1.026) > RC (0.792) > HCNs (0.681). 2Fe@HCNs demonstrated notable affinity for adsorbing both TC and Cu. Additionally, the influence of hydrochemical factors (i.e., cation species, anion species, and pH) on the adsorption properties of 2Fe@HCNs. Combined with advanced oxidation technology, the regeneration methods of magnetic adsorbent were explored using oxidizing agents (e.g., HO and peroxymonosulfate) as eluents which could increase the adsorption sites of magnetic carbon adsorbents during the regenerating process, which was the novelty of the study. Furthermore, the regeneration mechanisms of HO as eluent were investigated. This study discussed the application and regeneration methods of magnetic adsorbents in water treatment, offering new insights into environmental remediation using magnetic materials.