Preparation of a novel modified ceramic membrane for removal of nickel ions from aqueous phase

Abstract

A novel modified ceramic membrane (CM-SiO 2 -A) has been prepared with the depositing and grafting technologies for removal of Ni 2+ from aqueous solutions. Firstly, the silica was deposited onto the surface of initial ceramic membrane (CM) by using the in situ hydrolysis deposition method and activated to obtain the silanol groups. Then, 3-[2-(2aminoethylamino)ethylamino]propyl-trimethoxysilane was grafted onto the silica layer to obtain the CM-SiO 2 -A. The CM-SiO 2 -A was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, and thermogravimetric analysis. Further, the change of water flux and separation of Ni 2+ were studied by using the modified membrane. Results showed that the water flux of CM-SiO 2 -A was decreased by 84.79% compared with the CM. The CM-SiO 2 -A had a much higher total rejection rate of Ni 2+ (77.24%) than that of the un-grafted membrane (1.02%) at initial Ni 2+ concentration of 10 mg/L and exhibits the potential for separation of low concentration of Ni 2+ from aqueous solutions. Figure 1. Schematic diagram of ceramic membrane modification.Figure 3. SEM images of the surface of ceramic membranes: (a) initial ceramic membrane (CM); (b) ceramic membrane modified by grafting of AAAPTS (CM-SiO 2 -A).

Selective removal of tungstate anions from aqueous solutions by surface anion‐imprinted ceramic membranes

“…(b), the water flux of CM is 4850.2 L (m 2 h) −1 , while the water fluxes of IIP‐PEI/CM and NIP‐PEI/CM decrease to 3251.4 and 2920.7 L (m 2 h) −1 , respectively. These decreases of water fluxes are not very significant, compared with our previous work . The co‐deposition reduces the pore diameter, which can explain the reason of the decrease of water flux.…”

“…Pore size distributions (PSD) of CM, IIP‐PEI/CM and NIP‐PEI/CM were measured using the gas bubble pressure method, as described in our previous work . The water flux experiments were done at pressure difference of 0.2 bar and temperature of 25 °C …”