Fe-MOG-derived magnetic carbon aerogel from waste shatian pomelo peel for oxytetracycline adsorption

Waste Shatian pomelo peel was converted into a cellulose aerogel precursor. • An Fe-based MOG/cellulose carbon aerogel was fabricated by in situ growth. • The aerogel enabled efficient oxytetracycline adsorption and magnetic recovery. • The biobased adsorbent showed good recyclability and regeneration stability. Biomass aerogels often face a trade-off between adsorption capacity and recoverability in antibiotic removal. To address this limitation, Shatian pomelo peel, an abundant agricultural byproduct from pomelo processing, was used as a cellulose precursor to fabricate a pomelo peel-derived porous cellulose material (PPCM). An Fe-based metal-organic gel (MOG) was introduced in situ as an Fe-containing precursor, followed by high-temperature carbonization to prepare an Fe-MOG-derived magnetic carbon aerogel (FMCA) containing Fe species, a well-developed porous structure, and magnetic responsiveness. After response surface optimization, the resulting FMCA achieved an adsorption capacity of 836.1 mg g −1 for oxytetracycline (OTC) at an initial concentration of 100 mg L −1 and exhibited a saturation magnetization of 50.28 emu g −1 , enabling rapid magnetic separation under an external magnetic field. After five adsorption-desorption cycles, the material retained approximately 70% of its initial adsorption capacity. The kinetic and isotherm data were best described by the pseudo-second-order and Langmuir models, respectively. Combined pore-structure, zeta-potential, FT-IR, XPS, and batch adsorption results indicated that OTC uptake involved pore filling and multiple interfacial interactions. These results demonstrate that coupling in situ Fe-based MOG incorporation with carbonization is an effective strategy for simultaneously improving adsorption efficiency and recoverability in pomelo peel-derived aerogels, offering a promising route for agricultural byproduct valorization and antibiotic-contaminated water treatment. Download: Download high-res image (293KB) Download: Download full-size image