Preparation, characterization and biosorption properties of chitosan-mwcnts nanocomposite for removal of cadmium from aqueous solution

The removal of cd (ii) ions from aqueous solution by synthesized chitosan-mwcnts (ch-mwcnts) was investigatedin a batch adsorption system. the morphological of modified chitosan was characterized by scanning electronmicroscopy (sem), fourier transfer infrared spectroscopy (ft-ir) and thermogravimetric analysis (tga). theeffect of various factors such as; initial concentration of cadmium ions, initial ph and temperature of the solutionfor removal of cd (ii) was studied. the experimental isotherm data were analyzed by langmuir, freundlich,dubinin–radushkevich and temkin models. equilibrium data agreed well with langmuir isotherm, based on thismodel, the maximum adsorption capacity of nanocomposite of ch-mwcnts for cd (ii) was obtained to be 24.27mg/g at ph=6. a pseudo-second order model has been proposed to correlate the experimental data (r2= 0.996).the thermodynamic parameters such as standard gibb’s free energy (δg˚), standard enthalpy (δh˚), standardentropy (δs˚) and activation energy (ea) were evaluated by applying the van’t hoff and arrhenius equations andwere determined as -0.088 to -1.208 kj/mol , 16.6 kj/mol , 56 j/ mol. k and 5.58 kj/ mol, respectively.