Can reverse osmosis be backwashed?-Hezhong Environment (Beijing) Co., Ltd. was established in 2003

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Can reverse osmosis be backwashed?

Published Time:

2023-04-25

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Today, while casually discussing reverse osmosis cleaning, a colleague misspoke, saying "reverse osmosis reverse cleaning," and then seriously considered: Can reverse osmosis be cleaned in reverse?

After some research, here are two viewpoints for your reference. See which one you lean towards.

1 Viewpoint 1: Reverse cleaning is not possible.

The reason is based on the design principle of reverse osmosis. During backwashing, the reverse water flow and pressure will cause back pressure on the reverse osmosis membrane, damaging the desalination layer of the reverse osmosis membrane, reducing the desalination rate, and even causing failure.

As we all know, reverse osmosis, also known as reverse osmosis, is a membrane separation operation that separates a solvent from a solution using pressure difference as the driving force. Pressure is applied to one side of the membrane. When the pressure exceeds its osmotic pressure, the solvent will undergo reverse osmosis against the direction of natural osmosis. Thus, the permeated solvent, i.e., permeate, is obtained on the low-pressure side of the membrane; and the concentrated solution, i.e., concentrate, is obtained on the high-pressure side. Therefore, it is reasonable to believe that reverse flushing will damage the desalination layer, even low-pressure flushing requires inflow from the inlet end.

2 Viewpoint 2: Reverse cleaning is possible.

The reason is that when there is serious biological, colloidal, or particulate contamination, the contaminants can accumulate heavily on the first membrane at the inlet end. It is very difficult to break up these contaminants and allow them to flow through all the membrane elements in the pressure vessel. Therefore, cleaning fluid flowing in reverse can more easily wash away contaminants.

However, it should be noted that because the first reverse osmosis membrane does not have a thrust ring, reverse cleaning can easily cause the membrane element to be compressed and deformed. Therefore, there must be a limit on the flow rate and pressure during reverse cleaning. At the same time, if there is scaling at the end, these salt crystals must be removed first. If they are not cleared before reverse cleaning, the sharp salt crystals can easily damage the membrane surface, causing more serious damage, ultimately resulting in a worse situation.

Finally, it is recommended that you do not attempt reverse cleaning without sufficient funds and technical support.

These are two viewpoints on whether reverse osmosis can be cleaned in reverse. Which one do you lean towards? Welcome to comment.