The use of water hyacinth fibers to develop chitosan-based biocomposites with improved Cu2+ removal efficiency

This work investigated the use of water hyacinth fiber (WHF), extracted from the leaves of Eichhornia crassipes, to produce chitosan-based biocomposites for removal of copper(II) ions from water. The WHF was extracted by shredding, alkaline treatment, neutralization, and filtering. This yielded cellulosic fibers with an average diameter of 11 +/- 2 mu m. WHF/chitosan composite films were prepared using a solution casting method in which WHF was mixed with chitosan in an acidic aqueous solution and air-dried. X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used to characterize the biocomposites obtained. Tensile tests demonstrated a significant improvement in the Young's modulus when the composite was loaded with fiber at 5%. At a 10% loading, the composite film was found to adsorb approximately five times more copper(II) ions from water than the neat chitosan film (Cu2+ adsorption increased from 6.4 +/- 2.4 mg/g for the chitosan film to 34.1 +/- 2.2 mg/g for the composite containing 10% fibers). The equilibrium adsorption time was 240 min. The study successfully demonstrated the use of this aquatic weed in treatment of water with heavy metal ion-contamination.