Modified cellulose by polyethyleneimine and ethylenediamine with induced Cu(II) and Pb(II) adsorption potentialities.

In order to synthesize adsorbent that can effectively absorb heavy metals in a simple and economical way, this study described the fabrication of adsorbents based on cellulose acetate (CA). CA modified first by polyethyleneimine grafting (CAP) and then by ethylenediamine (CAPE) for enhancing Cu(II) and Pb(II) removal from water. The physico-chemical properties of the modified celluloses were analyzed. It was found that the adsorption functional groups (amino groups) were successfully grafted on cellulose and CAP converted from semi-crystalline to cellulose II after enhancement of ethylenediamine (EDA). Adsorption isotherm results showed that the Cu(II) and Pb(II) removal efficiency by CAPE was significantly higher than that by CAP, and CAP showed a higher adsorption capacity of Cu(II) and Pb(II) than CA, of which the adsorption isotherm modeled with Langmuir isotherms well. The adsorption capacity can significantly be affected by ionic strength and humic acid. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) results demonstrated the complexation between amino groups and Cu(II)/Pb(II) played an important role for adsorption onto CAPE.