Removal Of Nickel(Ⅱ) And Lead(Ⅱ) Using A Poly(Ethyleneimine)-functionalized Organic–inorganic Hybrid Silica Prepared

In this work, a hydrothermal-assisted surface grafting method was used for the synthesis of PEI-functionalized hybrid silica.The chemical structure of the solid prepared after grafting was characterized by infrared spectrum in order to confirm that PEI had been grafted onto the surface of silica gel particle. The surface area of the sample particles synthesized and silica gel particles were determined. The amino concentration of the sample particles synthesized was determined by acid–base titration analysis.The effect on adsorption capacity of Ni(II) and Pb(II) by contact time of the adsorption equilibrium, initial pH, the dosage of the adsorbent, temperature, initial concentration were investigated by single factor experiment method, the adsorption isotherm was fitted, then the adsorption kinetics and thermodynamic were studied.The poly(ethyleneimine)-functionalized organic–inorganic hybrid silica adsorbent was prepared by a hydrothermal-assisted surface grafting technique. The poly(ethyleneimine)-functionalized organic–inorganic hybrid silica adsorbent was characterized by FT-IR, nitrogen adsorption and the static adsorption-desorption experiment method. The static adsorption experiment results showed that poly(ethyleneimine)-functionalized hybrid silica adsorbent for Ni(II) and Pb(II) had high static adsorption capacity of 42.2 mg·g-1 and 68.1 mg·g-1 which was 1.6 times(27.1 mg·g-1) and 1.3 times(54.3 mg·g-1) as much as that of the sorbents by conventional heating method. The isothermal adsorption fit to Langmuir adsorption model. The poly(ethyleneimine)-functionalized hybrid silica adsorbent displayed a strong adsorption ability for Ni(II) and Pb(II) ion in the range of pH 4-8, offered a fast rate and reached an equilibrium state within 30 min. Kinetic studies indicated that the adsorption followed a pseudo-second-order model. Various thermodynamic parameters, such as ΔGo, ΔHo and ΔSo, were evaluated with the results indicating that this system was a spontaneous and endothermic process. The results indicated that poly(ethyleneimine)-functionalized hybrid silica adsorbent could be employed as an effective material for the removal of Ni(II) and Pb(II) from aqueous solutions.