A biodegradable based composite for wastewater treatment from cadmium and nickel ions

Cadmium and nickel ions were treated from wastewater by using (Chitosan/Gelatin/2-(Dimethylamino)ethyl methacrylate/silicon dioxide) composite (Cs/Gltn/PDMAEMA-SiO 2 )comp that was performed by gamma irradiation. Chemical treatment of parent hydrogel (Cs/Gltn/ PDMAEMA)gel was also done to introduce thiol groups in T-(Cs/Gltn/PDMAEMA). The characteristics of the composite compared with the parent and treated gels were examined by thermogravimetric analysis, X-ray diffraction, and field emission scanning electron microscopy. The adsorbent amount of the composite toward Cd 2+ and Ni 2+ was investigated. It was noticed that the maximum sorbent amount was performed at pH 5, 240 min contact time, and 10 g/L adsorbent dose. It can be also recognized that the sorption decreases as the temperature is increased. It is pointed to the exothermic adsorption character. The pseudo-second-order rate expression fits well the experimental data. The adsorption isotherm follows the Freundlich expression. The composite was tested for tenny wastewater treatment. It got a different trend from the obtained results indicated to some selectivity of this composite. The removal performance is 70% for heavy metal ions and 75% for color. The performance of other constituents is about 60%-70% except the turbidity is 46%.