Study on Preparation of Metal Ion Adsorbent by Grafting Binary Monomer on Alkali Wood Fiber With γ-Ray Co-Irradiation

The adsorption of heavy metals in wastewater using modified cellulose represents an environmentally friendly treatment method. In this research, acrylamide (AM) and acrylic acid (AA) were grafted onto alkali wood fiber (AWF) via ⁶⁰Co-γ irradiation to prepare the heavy metal adsorbent AWF-g-(AM-co-AA). This grafting method is efficient, ecofriendly, controllable, and widely applicable. Compared with monomer graft material or monomer material, the binary graft material has better adsorption properties, combining the advantages of both monomers while reducing the dosage. At an AM:AA ratio of 5:5, the grafting rate and grafting efficiency of AWF-g-(AM-co-AA) reached 196.17% and 58.85%, respectively, demonstrating excellent adsorption performance. Further optimization revealed that an AM:AA ratio of 8:2 achieved the highest grafting rate (232.97%) and grafting efficiency (69.86%), highlighting the flexibility and effectiveness of this approach. Key parameters such as treatment time, pH, and temperature were optimized, and the adsorption mechanism was thoroughly investigated. The optimal adsorption volume of AWF-g-(AM-co-AA) was 390 mg·g⁻¹ in a lead ion solution with an initial concentration of 500 mg·L⁻¹. These results highlight the promising industrial application of this adsorbent for heavy metal removal.