High Efficient Dye Adsorption and Facile Magnetic Recovery of PVA/XG/Fe ₃ O ₄ Hydrogel via Green In Situ Synthesis Strategy

To tackle dye‐related water pollution, developing cost‐effective adsorbents with high efficiency in removing residual dyes from wastewater is of vital importance. Herein, magnetic composite hydrogels designed for dye adsorption and recyclability is synthesized by combining polyvinyl alcohol (PVA), xanthan gum (XG), and iron (II, III) oxide (Fe 3 O 4 ) magnetic nanoparticles. The PVA/XG hydrogel matrix is fabricated via freeze–thaw technique, and the Fe 3 O 4 nanoparticles are generated in situ within the hydrogel network. The structural and functional characteristics of the PVA/XG/Fe 3 O 4 magnetic hydrogels are systematically investigated using swelling behavior, turbulence stability, thermogravimetric analysis, and scanning electron microscopy. The impacts of adsorbent dosage, initial concentration, and solution pH on adsorption properties are comprehensively evaluated. Furthermore, the adsorption mechanisms of congo red (CR) and methylene blue (MB) onto the hydrogel are elucidated via kinetics studies, isotherm modeling, thermodynamic analyses, and Fourier transform infrared characterization. The Langmuir adsorption isotherm models predicted maximum adsorption capacities of 364.70 and 409.19 mg g −1 for MB and CR, respectively. A novel PVA/XG/Fe 3 O 4 magnetic hydrogel is developed that addresses a critical challenge in water treatment: the cumbersome recovery of adsorbents. By integrating rapid magnetic separability with high adsorption capacity, this material provides an innovative and sustainable solution for environmental remediation.