Metal-organic frameworks (MOFs) have been considered as promising nanofillers to fabricate mixed matrix membranes for water treatment. However, manipulating distribution of MOFs nanoparticles in the membrane matrix remains a great challenge. In this study, UiO-66 was firstly coated by magnetic Ni via an in-situ reduction reaction, and then incorporated into polyethersulfone (PES) membrane matrix to prepare PES-Ni@UiO-66 membrane. The magnetic Ni allowed to manipulate the distribution of magnetic Ni@UiO-66 in the phase-inversion process by an external magnetic field. The hydrophilic Ni@UiO-66 can be pulled onto membrane surface by the magnetic force, endowing the prepared membrane with rather higher hydrophilicity. The prepared membrane exhibited superior water permeability with a pure water flux of 611.5 ± 19.8 L·m −2 ·h −1 and improved antifouling performance. Moreover, benifiting from photocatalytic activity of the exposed Ni@UiO-66 on membrane surface, the obtained PES-Ni@UiO-66 membrane demonstrated excellent photocatalytic self-cleaning ability with a flux recovery rate (FRR) higher than 95% under UV irradiation. Analyzing by extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory indicated that the improved antifouling performance could be attributed to less attractive or even repulsive interaction between the prepared membrane and pollutants. This work provided valuable guidance for structural regulation and development of high-performance MOFs-based membranes for water treatment.
Guizhen Li,Yao Zhang,Xinyu Hu,Wei Tan,Jiaxiong Li,Daiyan Su,Hongbin Wang,Min Yang
In the present study, Ni-UiO-66 was synthesized to improve the adsorption efficiency of tetracycline (TC) in wastewater treatment . To this end, nickel doping was performed in the preparation process of UiO-66. The synthesized Ni-UiO-66 was characterized by XRD , SEM and EDS, BET, FTIR, TGA , and XPS for obtaining the lattice structure, surface topography, specific surface area, surface functional groups, and thermostability. More specifically, Ni-UiO-66 has a removal efficiency and adsorption capacity of up to 90% and 120 mg g −1 , respectively, when used to treat TC. The presence of ions HCO 3 − , SO 4 2− , NO 3 − and PO 4 3− slightly affects the TC adsorption. A 20 mg L −1 humic acid reduces the removal efficiency from 80% to 60%. The performed analyses revealed that Ni-UiO-66 had similar adsorption capacity in wastewater with different ion strengths. The variation of adsorption capacity with the adsorption time was fitted using a pseudo-second-order kinetic equation . Meanwhile, it is found that the adsorption reaction occurs only on the monolayer of the UiO-66 surface so the adsorption process can be simulated using the Langmuir isotherm model. The thermodynamic analysis indicates that the adsorption of TC is an endothermic reaction . Electrostatic attraction, hydrogen-bond interaction, and π-π interaction might be the main reasons for the adsorption. The synthesized Ni-UiO-66 has well adsorption capacity and stable structure. Accordingly, it is expected to achieve a good prospect in industrial applications and wastewater treatment plants .
危险品化学品经营许可证（带存储）