Adsorption of Heavy Metal Ion from Aqueous Solution by Using Cellulose Based Hydrogel Composite

Batch experiments of adsorption of heavy metals cations from aqueous solution by using carboxymethyl cellulose-graft-poly(acrylic acid)/monmorilonite (CMC-g-PAA/MT) hydrogel composite were carried out. The parameter such as different pH and the presence of other ions as competitor were studied to observe their effects on the adsorption capacity of the hydrogel composite. The results showed that the adsorption of metal ions by the hydrogels was higly pH dependent, and maximum adsorption was obtained at pH 5.0. At this pH, the adsorption capacities of hydrogels for the Pb2+ and Zn2+ ions were 146.19 mg/g and 286.67 mg/g, respectively. The hydrogels can be regenerated after releasing metal ions by washing with low pH solution and reused two times. Based on the scanning electron microscope (SEM) images and Fourier transform infrared spectroscopy (FTIR) spectra before and after adsorption by the hydrogels revealed that the complex formation between heavy metal ions and carboxyl groups of the hydrogels was the main adsorption mechanism.