Polyamide nanofiltration membrane prepared by regenerating scrapped microfiltration membrane and method

Abstract

The invention provides a polyamide nanofiltration membrane prepared by regenerating a scrapped microfiltration membrane and a method. The method utilizes a cleaning-repairing-interfacial polymerization step upgrading strategy, adopts sodium hypochlorite-oxalic acid to perform deep cleaning on the scrapped microfiltration membrane, and uses polydopamine as a repairing agent to construct a reaction platform on the membrane surface; finally, the polyamide nanofiltration membrane with a polyamide active layer is formed by utilizing a piperazine and trimesoyl chloride reaction system, a coating with a certain thickness and good hydrophilicity can be constructed on the surface of the membrane through repairing, and a good base membrane condition is provided for upgrading and preparing the nanofiltration membrane. According to the method provided by the invention, the application scene of the actual waste film is widened, the service lifetime of the film is prolonged, and the resource recycling is further promoted. The method is simple in preparation process, easy to implement, low in cost, environmentally friendly and high in practical significance, an effective means is provided for solving the problem of recycling of polluted / scrapped low-pressure membranes, and a green recycling chain between the low-pressure membranes and the high-pressure membranes is broken through.

Description

technical field [0001] The invention belongs to the technical field of membrane separation, and in particular relates to a polyamide nanofiltration membrane and a method prepared by regeneration of scrapped microfiltration membranes. Background technique [0002] Microfiltration membranes are widely used in the field of water treatment membrane separation technology, especially in membrane bioreactors. However, due to the presence of membrane fouling, commercial microfiltration membranes face the problem of water flux decline during use. Although its flux can be restored after membrane cleaning, after multiple rounds of pollution-maintenance cleaning and restorative cleaning cycles, the microfiltration membrane will reach the end of its life in about 5-7 years and become a scrap membrane, which must be replaced with a new membrane To maintain the normal operation of the reactor. According to statistics, by 2020, the global membrane module market is expected to reach 20 bil...

AI Technical Summary

Problems solved by technology

In actual operation, due to the complexity of the influent water quality, which contains a large amount of particles, colloids, etc., it will cause greater damage to the surface and interior of the membrane. At the same time, cleaning will often have a greater impact on the filtration performance of the membrane, and accelerate the membrane module. Aging speed, affecting its mechanical properties, etc.

Images