Efficient removal of heavy metal ions from aqueous solution using salicylic acid type chelate adsorbent

Abstract: In this study, 5-aminosalicylic acid was successfully grafted onto the poly(glycidyl methacrylate) (PGMA) macromolecular chains of PGMA/SiO2 to obtain a novel adsorbent designated as ASA–PGMA/SiO2. The adsorption properties of ASA–PGMA/SiO2 for heavy metal ions were studied through batch and column methods. The experimental results showed that ASA–PGMA/SiO2 possesses strong chelating adsorption ability for heavy metal ions, and its adsorption capacity for Cu2+, Cd2+, Zn2+, and Pb2+ reaches 0.42, 0.40, 0.35, and 0.31mmolg−1, respectively. In addition, pH has a great influence on the adsorption capacity in the studied pH range. The adsorption isotherm data greatly obey the Langmuir and Freundlich model. The desorption of metal ions from ASA–PGMA/SiO2 is effective using 0.1moll−1 of hydrochloric acid solution as eluent. Consecutive adsorption–desorption experiments showed that ASA–PGMA/SiO2 could be reused almost without any loss in the adsorption capacity. [Copyright &y& Elsevier]