Nonmetal multi-doped nTiO2-based visible light catalysis hollow fiber ultrafiltration membrane and preparation method

Abstract

The invention discloses a nonmetal multi-doped nTiO2-based visible light catalysis hollow fiber ultrafiltration membrane and a preparation method, and belongs to the technical field of membrane separation. The preparation method comprises the steps that 10.0%-25.0% (w / w) of polysulfone or polyether sulfone, 8.0%-17.0% (w / w) of a pore-forming agent, 0.1%-2.0% (w / w) of a surfactant, 0.1%-5.0% (w / w) of nonmetal multi-doped nTiO2 and 51.0%-81.8% (w / w) of a solvent are added into a dissolving tank according to a certain order and stirred to be dissolved for 5-16 hours at the temperature of 35 DEG C to 95 DEG C until the materials are completely dissolved, standing defoaming is conducted for 8-36 hours, and casting membrane liquid is prepared; the visible light catalysis hollow fiber ultrafiltration membrane is prepared by adopting a traditional dry-wet-process spinning technology. According to the ultrafiltration membrane prepared through the method, the pure water flux is higher than or equal to 330 L / m<2>.hr.0.1 MPa, the bovine serum albumin retention rate is higher than or equal to 90.00%, the fulvic acid degrading removal rate is higher than or equal to 65% (under simulation visible light, operation is conducted for 1 hour), and the good anti-pollution performance and visible light catalysis performance are achieved. The ultrafiltration membrane is particularly suitable for micro-polluted source water advanced treatment, sea water desalination pretreatment and advanced treatment and recycling of biochemical engineering and medicine field wastewater.

Description

technical field [0001] The invention relates to a polymer mixed matrix ultrafiltration membrane and a preparation method thereof, in particular to a non-metal multi-doped nTiO 2 Visible light catalytic hollow fiber ultrafiltration membrane and preparation method thereof. Background technique [0002] The scarcity of water resources and increasingly serious water pollution have become bottlenecks restricting social progress and economic development. The development of new water sources and the utilization of waste water resources have also become issues of global concern. Due to the extremely rich water resources in Shanghai and the large amount of waste water generated, the recycling of sewage and seawater desalination have become strategic choices to solve the water resource crisis. Among many sewage resource technologies, membrane separation technology is one of the best choices. [0003] Mixed matrix membrane, also known as hybrid membrane, is a membrane formed by chemi...

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Problems solved by technology

[0005] Chinese patent CN102989329A passed AgNO 3 、TiO 2 Blending modification to prepare ultrafiltration membranes, in fact, mainly uses AgNO 3 visible light catalytic activity, and the degradation rate is slow (in the patent, the degradation rate of methylene blue is characterized by light for 10 hours), and it is impossible to prepare a separation membrane for separation and visible light catalysis at the same time; 3 PO 4 / TiO 2 Complex (Ag 3 PO 4 Nanoparticle deposition onto TiO 2 Surface) and polyvinylidene fluoride materials are blended and modified, so that the modified film has visible light catalytic antibacterial and antifouling properties, mainly using the deposited on TiO 2 Ag on the surface 3 PO 4 Particles degrade the organic matter adsorbed during the application of the separation membrane to reduce membrane fouling, and have not been used to prepare a separation membrane with both separation and visible light catalytic properties; at the same time, neither of these two patents has made full use of silver salts and TiO through synergistic effects 2 The catalytic performance of silver salt or silver salt and TiO is only utilized by blending or deposition 2 Respective catalytic activity, visible light catalytic efficiency is low

Chinese patent CN102895888A prepares a titanium dioxide / polyvinylidene fluoride film first, then absorbs and reduces silver ions on its surface to prepare a visible light-responsive polyvinylidene fluoride film, and the methylene blue degradation rate of the prepared film is 33% to 51% (visible light irradiation 100mins); but this invention needs to complete the preparation of the patented product after the preparation of the titanium dioxide / polyvinylidene fluoride film, and then through the steps of absorbing silver ions, reducing silver ions to simple silver, and vacuum drying, and the preparation process requires a dark room , ultraviolet irradiation, vacuum drying and other conditions, the process is complicated, the preparation cost is high, and the industrialization is difficult

Chinese patent CN104383821A uses graphene oxide to support magnetic particles with a core-shell structure @TiO 2 The modified separation membrane was prepared, and it was believed that the separation membrane showed good photocatalytic degradation performance and protein pollution resistance performance for the target pollutant bovine serum albumin, but the separation performance and visible light catalytic degradation performance of the prepared membrane were not clarified in the patent application advantages and disadvantages, and the preparation process of the separation membrane is complicated; at the same time, the magnetic particles @TiO 2 The preparation method is complicated and the cost is high

The present invention adopts nTiO 2 Multi-doping of non-metals to give full play to a variety of non-metals and nTiO 2 The synergistic effect further enhances the nTiO 2 Visible light catalytic activity, and using non-metal multi-doped nTiO 2 Improve the visible light photocatalytic properties of polymer ultrafiltration membranes, prepare hollow fiber mixed matrix ultrafiltration membranes with visible light catalytic activity and realize industrialization. So far, no similar visible light catalytic hollow fiber ultrafiltration membrane products have been produced in China. There are no related literature reports