Fast removal of Cu(II) and Hg(II) from aqueous solutions using kaolinite containing glycidyl methacrylate resin

摘要

A clay-polymer chelating resin was prepared through copolymerization of glycidyl methacrylate (GMA) with N,N'-methylene bis-acrylamide (MBA) as a cross-linker in the presence of 5% kaolinite mineral. The resin obtained was chemically modified through the reaction with tetraethyle-nepentamine (TEP). A comparison study was held between the modified clay-containing resin and a clay-free one. The prepared resins were characterized by FT-IR, XRF, TGA, BET-surface area and SEM techniques. The adsorption behavior of both resins towards Cu (II) and Hg (II) at different conditions was studied. Kinetics, isotherms and thermodynamic parameters of the adsorption process were also investigated. The clay-containing resin exhibited a higher thermal stability, greater surface area and higher uptake values than the clay-free one. Uptake values up to 2.38 mmol/g (479.57 mg/g) for Hg (II) and 1.95 mmol/g (124.02 mg/g) for Cu (II) were reported on the clay-containing resin. The adsorption process of both metal ions followed Langmuir and Freundlich isotherms and is dominated by enthalpic rather than entropic changes. The regeneration of the loaded resin was carried out using KI and HC1 for elution of Hg (II) and Cu (II), respectively.