Removal of benzo[a]anthracene by DNA-loaded aerogel microspheres and mechanism elucidation via spectroscopic methods

With the rapid development of industry, polycyclic aromatic hydrocarbon (PAH) pollution has become increasingly severe, posing significant risks to human health and other organisms. Developing effective remediation strategies is urgently needed. In this study, the intercalation of benzo[a]anthracene (B[a]A) with DNA was elucidated using UV absorption spectroscopy and resonance light scattering spectroscopy, revealing a binding constant of 2.0752 × 10 6 L mol −1 . Subsequently, DNA/calcium alginate magnetic aerogel microspheres were prepared for the removal of B[a]A from aqueous solutions. The aerogel microspheres exhibited an irregular spherical morphology with a concave-convex surface structure, demonstrated strong water absorption capacity, and contained predominantly mesoporous structures. These microspheres displayed excellent adsorption performance for B[a]A and could be efficiently separated via magnetic means. At an initial B[a]A concentration of 350 μg L −1 , the removal efficiency reached 98.52 %. The adsorption process was best described by the Langmuir isotherm model and pseudo-second-order kinetics. For natural river water samples spiked with B[a]A, the removal efficiency remained above 98.45 % across a concentration range of 50–300 μg L −1 . The aerogel enables simple and rapid adsorption of benzo[a]anthracene, and the gel can be quickly retrieved using a magnet, demonstrating excellent application potential.