Postconsumer high-density polyethylene/agave fiber foamed composites coated with chitosan for the removal of heavy metals



Composites of postconsumer high-density polyethylene with agave fiber were prepared by single-screw extrusion with azodicarbonamide as a foaming agent to increase the surface area; the composite pellets were coated with chitosan afterward. A chemical pretreatment was applied to the pellets to enhance the chitosan gel compatibility. The adsorption capacities of the composites coated with chitosan were evaluated for Cd(II) and Cu(II) removal from aqueous solutions. The coated composites were characterized by scanning electron microscopy, attenuated total reflectance infrared spectroscopy, and X-ray photoelectron spectroscopy. Atomic absorption spectroscopy was used to measure metal uptake in batch adsorption studies. The results of this study demonstrated the composites' ability to immobilize chitosan on their surfaces and their capacity to adsorb metal ions. The equilibrium isotherms for Cd(II) and Cu(II) adsorption on the chitosan-coated composites were described by the Langmuir model. This material represents an attractive low-cost recycled material for adsorbing metal ions from polluted waters. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010