Preparation of amino-functionalized silica for copper removal from an aqueous solution

In the present research, amino-functionalized silica materials were synthesized to develop absorbents for removing copper (II) ions from water. Three kinds of silica with various BET surface areas and pore volumes (331.4 m2/g, 460.1 m2/g, 717.7 m2/g and 1.38 cm3/g, 1.06 cm3/g, 0.57 cm3/g, respectively) were used to determine an optimum material. 3-Aminopropyltrimethoxysilane (3-APTMS) and N-[3-(trimethoxysilyl)propyl]-ethylenediamine (MSDA) are two amino-functional moieties grafted onto silica surfaces. A maximum copper absorption of 33.45 mg/g was confirmed using the amino-functionalized material at an initial 3-APTMS concentration of 2.52 mmol/g. Silica with a BET surface of 331 m2/g and a pore volume of 1.38 cm3/g demonstrated a good copper absorption capacity. Interference species such as pH, NH3 and EDTA were also studied in this work.