L-Glutamic Acid Crosslinked Cellulose Ester Films for Heavy Metal Ions Adsorption

Abstract

A chemically crosslinked cellulose ester films (MCC-CAD-GA) based on cellulose (MCC), citric acid anhydride (CAD) and l-glutamic acid (l-GA) was successfully prepared via amidation for the adsorption of Cd2+, Co2+, Ni2+, Pb2+ and Cu2+ ions with lower concentration from water. The obtained composites were characterized by FTIR, XRD, elemental analysis and SEM. The results showed that the thermal stability and mechanical strength of MCC-CAD-GA films were enhanced. The adsorption parameters, such as temperature, contact time, adsorbent dose, pH, and initial metal ion concentration were optimized. The adsorption capability of the composite for heavy metal ions was substantially and synergistically improved by adding l-GA into MCC-CAD. The composite films could be recycled and exhibited constant adsorption ability for five successful runs. In addition, the adsorption behavior followed the pseudo-second order kinetic model, and the adsorption isotherms were well described by the Langmuir model. All the results suggested that the MCC-based composite films could be considered as a promising candidate for heavy metal ions treatment. A chemically crosslinked cellulose ester films based on cellulose (MCC), citric acid anhydride (CAD) and l-glutamic acid (l-GA) was successfully prepared via amidation for the adsorption of Cd2+, Co2+, Ni2+, Pb2+ and Cu2+ ions with lower concentration from water. The modified could be recycled and exhibited constant adsorption performance for five successful runs.