Acrylic acid-chitosan blend hydrogel: a novel polymer adsorbent for adsorption of lead(II) and copper(II) ions from wastewater

Environmental pollution due to heavy metal contamination is a major environmental concern. A fully biodegradable and reusable adsorbent hydrogel for removal of heavy metal ions has been developed. The hydrogel was prepared from acrylic acid and chitosan using an irradiation method. The adsorbent was characterized using Fourier transform infrared analysis. Uptake of copper(II) and lead(II) at different contact times, pH, and metal ion concentrations was investigated by a batch method using atomic absorption spectroscopy. Kinetic adsorption data were studied using pseudo-first-order and pseudo-second-order equations. Experimental metal adsorption data were fitted with the Langmuir isotherm model. The maximum adsorption capacity of the hydrogel was found to be 192 and 171 mg/g for lead(II) and copper(II), respectively, from the Langmuir isotherm model. Reuse and desorption of the hydrogel were also successful. The adsorbent can be used to adsorb Cu(II) and Pb(II) by the column method with high removal efficiency. The data indicated that the designed hydrogel was environment friendly, regenerative, and can be used effectively for the removal of toxic heavy metal cations from wastewater for a sustainable environment.