Adsorption of metal ions using silica particles modified with 2-(2ʹ-hydroxyphenyl)benzothiazole

In this study, a new material for removal of metal ions from water samples was prepared by the chemically functionalization of silica gel. The organic ligand 5-chloro-2-(2'-hydroxyphenyl)benzothiazole (HPBT) was synthesized and HPBT was chemically immobilized onto silica surface (Si-L). The newly synthesized ligand has been characterized by FT-IR, elemental analysis and H-NMR. SEM, EDX, N2 adsorption, elemental analysis and FT-IR have been used to characterize the structure of silica particles before and after functionalization. This new synthesized Si-L adsorbent was used for the removal of heavy metal ions such as Cu(II), Pb(II), Cd(II), Co(II) and Ni(II) from water samples. The effects of initial concentration of metal ions, adsorption time and solution pH were investigated. The selective removal of Cu(II), Pb(II), Cd(II), Co(II) and Ni(II) from aqueous solutions in single, binary and five component systems were examined. The experimental isotherm data were analyzed using Langmuir, Freundlich, and Dubinin Raduskevizch (D-R) isotherm models. The adsorption capacity of Si-L particles is found to be 20±0.50, 69±0.55, 25±0.35, 14±0.50 and 23±0.60 mg/g (0.315±0.008, 0.333±0.003, 0.222±0.004, 0.238±0.009 ve 0.392±0.01 mmol/g) for Cu(II), Pb(II), Cd(II), Co(II) and Ni(II) respectively. Mixture of 0.1 M EDTA - 0.01 M HCl was used for desorption of investigated metal ions from the Si-L particles. Furthermore, the adsorption performance of Si-L particles was investigated in synthetic wastewater sample.