Method and device for slowing down pollution of reverse osmosis membrane and nanofiltration membrane by utilizing soaking of medicament

Abstract

The invention discloses a method and a device for slowing down the pollution of a reverse osmosis membrane and a nanofiltration membrane by utilizing soaking of medicament, belonging to the water treatment in the environment-friendly field. According to the device, a medicament feeding system is arranged in a water treatment system, a medicament box, a medicament feeding pump and a membrane processing system are communicated by pipes, two branch pipes are arranged at a water outlet of the membrane processing system, one branch pipe is connected with a producing water storage tank, and a producing water discharge electric valve is arranged on the other branch pipe; a raw water tank, a raw water pump, a high-pressure pump and the membrane processing system are sequentially connected by another pipe, and a condensed water discharge valve is further arranged on the other end of the membrane processing system. When the device is required for slowing down the pollution of the reverse osmosis membrane and the nanofiltration membrane, the water treatment system is stopped, and raw water in the membrane processing system is replaced by medicament liquid in the medicament box entirely; after a certain time, the water treatment system is opened, the medicament feeding system is closed, and the system can run normally to produce water. According to the method and the device, the service lives of the reverse osmosis membrane and the nanofiltration membrane can be prolonged, and the water treatment cost and equipment maintenance cost can be lowered.

Description

technical field [0001] The invention belongs to the direction of water treatment in the field of environmental protection, in particular to a device and method for slowing down the pollution of reverse osmosis membranes and nanofiltration membranes by using medicament soaking. Background technique [0002] There are various forms of substances in the feed water of the water treatment system that can cause reverse osmosis and nanofiltration membrane surface fouling, such as hydrated metal oxides, calcium-containing precipitates, organic matter and microorganisms, although these substances are fully removed in the pretreatment process , but still a small amount of residual substances enter the membrane treatment system. With the accumulation of these substances on the surface of the membrane, various foulings are formed, resulting in a decrease in the water production of the system, a decrease in the desalination rate, an increase in the pressure difference between the stages, ...

AI Technical Summary

Problems solved by technology

[0002] There are various forms of substances in the feed water of the water treatment system that can cause reverse osmosis and nanofiltration membrane surface fouling, such as hydrated metal oxides, calcium-containing precipitates, organic matter and microorganisms, although these substances are fully removed in the pretreatment process , but still a small amount of residual substances enter the membrane treatment system. With the accumulation of these substances on the surface of the membrane, various foulings are formed, resulting in a decrease in the water production of the system, a decrease in the desalination rate, an increase in the pressure difference between the stages, and a decrease in the overall performance of the system.

[0003] When reverse osmosis and nanofiltration water treatment systems are used in rural areas and some small-scale beverage manufacturers, due to the non-24-hour continuous operation of the equipment, frequent interruptions, long start-stop intervals, and long-term immersion of membrane elements in concentrated water, resulting in highly susceptible to contamination

At present, the industry mainly adopts regular CIP online cleaning technology, and the cycle is generally 3 to 6 months. In fact, a large amount of dirt has accumulated on the surface of the membrane during such a long period of time, and it is difficult to completely remove these dirt by short-term online cleaning. , if you continue to use these membrane elements that have not been thoroughly cleaned, it will lead to a decrease in the quality of the system's permeated water, an increase in the cost of water treatment per ton, and a reduction in the life of the membrane elements

Images