Treatment method for nanofiltration membrane central water purification system

Abstract

The invention discloses a treatment method for a nanofiltration membrane central water purification system. A raw water tank is connected with a water inlet opening of a quartz sand filter through a raw water pump; a water outlet opening of the quartz sand filter is connected with an ozone contact tower; an ozone gas inlet opening formed in the bottom of the ozone contact tower is connected with an ozone generator through a high-pressure fan; a water outlet opening of the ozone contact tower is connected with a water inlet opening of an active carbon filter through a carbon filtering pump; a water outlet opening of the active carbon filter is connected with a middle water tank; a water outlet opening of the middle water tank is connected with a fine filter through a pressurizing pump; a water outlet opening of the fine filter conveys water into a nanofiltration membrane filter through a high-pressure pump; a water outlet opening of the nanofiltration membrane filter is provided with an ultraviolet sterilization lamp, and is connected with a finished product water storage tank through a water outlet pipeline of the ultraviolet sterilization lamp; two branch pipes are arranged at a concentrated water outlet of the nanofiltration membrane; the first branch pipe is connected with a concentrated water recycling device; and the second branch pipe is connected with a water inlet opening of the raw water pump. The treatment method has the advantages that the chlorine resistance and the oxidative resistance of the composite nanofiltration membrane are improved by 5 times or higher; the water flux of the composite nanofiltration membrane is improved by 20 to 50 percent; the contamination-resistant performance of the composite nanofiltration membrane is improved by two times or higher; and the water yield of the central water purification system is improved to 70 percent or higher.

Description

technical field [0001] The invention relates to a water treatment system and a treatment method thereof, in particular to a treatment method for a nanofiltration membrane central water purification system, belonging to the technical field of water treatment. Background technique [0002] Nanofiltration membrane is also known as low-pressure reverse osmosis or loose reverse osmosis membrane. Because its surface layer density is lower than that of reverse osmosis membrane, it can obtain much higher water flux than reverse osmosis membrane, and at the same time, the The above ions and organic molecules with a molecular weight greater than 200 have a sufficiently high interception capacity, and their application range is becoming wider and wider. However, although the polyamide-based nanofiltration composite membrane has excellent desalination performance and water permeation performance, the membrane performance drops sharply in the presence of oxidative components. In the pas...

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Problems solved by technology

Another major disadvantage of nanofiltration membranes is that their anti-fouling ability is very weak. Many potential pollutants in raw water, such as colloids, proteins, microorganisms, and hard water ions that are easy to scale, are likely to cause fouling of the membrane, making the membrane performance rapid. Attenuation, which requires additional pretreatment to remove these components as much as possible, which also increases the cost of membrane use

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