The efficient adsorption and removal of levofloxacin by hyperbranched polyamide-aminated dialdehyde cellulose hydrogel

Abstract

Levofloxacin (LEV), a widely used quinolone antibiotic, persists in aquatic environments and is difficult to degrade. Its significant toxicity can exacerbate the spread of antibiotic resistance through environmental transmission, making it a pollutant that urgently requires attention. As a new type of porous adsorbent material, hydrogels offer abundant adsorption sites during the adsorption process, making them widely used in water pollution treatment. In the present work, sodium periodate was used to oxidize cellulose to synthesize easily modified diacetyl cellulose (DAC). Subsequently, hyperbranched polyamides (HBP) containing multiple amine groups were ammoniated and crosslinked with DAC. Hyperbranched ammoniated double aldehyde cellulose hydrogels (HBP-DAC@SA) featuring a three-dimensional porous structure were prepared. The microstructure of HBP-DAC@SA was analyzed to investigate the adsorption performance of HBP-DAC@SA on LEV pollutants. The effects of synthesis temperature, pH, and HBP-DAC dosage on the adsorption properties of LEV were investigated through orthogonal experiments. The adsorption capacity of HBP-DAC@SA for LEV reaches up to 216.72 mg·g⁻¹. The adsorption kinetics and adsorption isotherm data are consistent with the quasi-secondary adsorption model and the Langmuir isothermal adsorption model, respectively. Furthermore, the adsorption capacity of HBP-DAC@SA remained at 80 % of its initial capacity after 14 cycles of adsorption/desorption. HBP-DAC@SA is easily recyclable and exhibits excellent reusability. Consequently, it can serve as an effective adsorbent material for treating LEV pollution.