Removal of silver (I) from aqueous solutions by chitosan/carbon nanotube nanocomposite beads

Abstract

Chitosan/CNT nanocomposites were prepared by blending chitosan with carbon nanotubes (CNTs) and forming composite beads. The composites were used as Ag+ adsorbents. Adsorption equilibrium experiments were carried out as a function of contact time, CNTs concentration, pH value, and adsorbent dosage level. The equilibrium time of Ag+ adsorption was found to be 160 min. Composite adsorbent had the highest adsorption efficiency when the weight of CNTs was 0.01 wt%. The maximum Ag+ removal took place at the initial pH value of 3. The optimum adsorbent dosage for Ag+ removal was 5 g. Under above optimal conditions the maximum Ag+ removal was 99.7%. The adsorption isotherm of chitosan/CNT nanocomposite bead agreed well with the Langmuir model. The maximum adsorption capacity was 0.393 mg/g. © (2014) Trans Tech Publications, Switzerland.