Abstract
Silver nanoparticles coated with chitosan (AgNPs) and AAm/HEMA/Ag nanocomposites synthesized by using Co-60 gamma radiation cell at a dose rate of 2.8 kGy/h and used for uptake of mercury from wastewater. To study the various properties of the nanocomposites different characterization techniques such as XRD, TEM, FTIR, and SEM were applied. Water uptake for all AAm/HEMA hydrogels studied under the effect of many factors was studied in detailed. Based on the water uptake results the AAm/HEMA (1:0.5 v/v) composition was used as a precursor for preparation AAm/HEMA/Ag nanocomposite hydrogel. By examining, the possibility of using the prepared hydrogels and nanocomposite hydrogel for adsorption of Hg2+ the results showed that the adsorption processes depend on time, initial concentration, dose of adsorbent and pH value. The adsorption capacity increase as pH increased up to pH 5. Then started decreasing at pH values higher than pH 5. The pseudo-first order and pseudo second order used to evaluate the kinetic models and the mechanism of the adsorption. Results showed that the adsorption kinetics best fit the pseudo-second-order model. Thermodynamic data revealed spontaneous exothermic processes and was a physisorption reaction. In addition, results show that the AAm/HEMA/Ag nanocomposite has high efficiency for removing Hg (II) ions from wastewater containing.