Poly(methacrylic acid)-grafted chitosan microspheres via surface-initiated ATRP for enhanced removal of Cd(II) ions from aqueous solution

摘要: Abstract Cross-linked chitosan (CCS) microspheres tethered with pH-sensitive poly(methacrylic acid) (PMAA) brushes were developed for the efficient removal of Cd(II) ions from aqueous solutions. Functional PMAA containing dense and active carboxyl groups ( COOH) grafted onto CCS microsphere surface via surface-initiated atom transfer radical polymerization (ATRP). Batch adsorption results showed that solution pH values had a major impact on cadmium by PMAA-grafted optimal observed above 5. The CCS-g-PMAA was found to achieve equilibrium within 1 h, much faster than about 7 h microsphere. At 5 an initial concentration 0.089–2.49 mmol dm−3, maximum capacity Cd(II), derived Langmuir fitting around 1.3 mmol g−1. Desorption cycle experimental revealed loaded can be effectively regenerated in dilute HNO3 solution, remained almost unchanged upon five reuse.