Method for recycling scrapped low-pressure membrane based on interface wettability regulation, and polyamide nanofiltration membrane prepared by method

Abstract

The invention provides a method for recycling a scrapped low-pressure membrane based on interface wettability regulation, and a polyamide nanofiltration membrane prepared by the method. According to the method, after a loose mud cake layer on the surface of the scrapped membrane is hydraulically cleaned, the polluted and hydrophobic surface of the scrapped low-pressure membrane is used as a reaction platform, a surfactant is introduced into a piperazine and trimesoyl chloride reaction system, the interface wettability is regulated and controlled, the interfacial tension between a water phase and an organic phase in the interfacial polymerization process is reduced, a polyamide active layer is formed through condensation polymerization, and the high-selectivity polyamide nanofiltration membrane is obtained. According to the method provided by the invention, the environmental burden caused by landfill of the scrapped film is avoided, the preparation process is simple to operate and low in cost, a green recycling chain between the low-pressure film and the high-pressure film is effectively broken through, and resource recycling is promoted.

Description

Technical field [0001] The present invention belongs to the field of membrane separation technology, and more particularly to methods based on interfacial wettability regulatory film recycling utilization and the prepared polyamide nanofiltration membrane. Background technique [0002] Polyvinylidene fluoride (PVDF), polyether sulfone (PES), etc., high, chemical stability, and thermal stability, are widely used in the field of water treatment and sewage treatment, such as membrane bioreactors (MBR). Although the membrane separation process is superior to most water treatment processes in footprint, the commercial organic forming film is poor. In the long-term pollution-cleaning cycle, the water permeability of the membrane is inevitably reduced due to physical and chemical cleaning recovery, and the film is not necessarily reduced. When the water supply demand cannot be satisfied, the film reaches the life of life (usually 5 to 8 years. . Typically, the scrap membranes reaching t...

AI Technical Summary

Problems solved by technology

During the long-term use of the membrane, periodic chemical cleaning makes the surface of the scrapped membrane very hydrophobic, and the absorption efficiency of amine monomers is low. It is difficult to form a highly selective polyamide active layer through interfacial polymerization, which hinders the regeneration of the scrapped membrane and upgrades it to a high-pressure membrane.

Images