A quick and easy method for identifying the types of membrane fouling in reverse osmosis operation-Hezhong Environment (Beijing) Co., Ltd. was established in 2003

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A quick and easy method for identifying the types of membrane fouling in reverse osmosis operation

Published Time:

2022-07-27

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►Organic/Colloid Fouling

Organics in the feed water adsorb to the membrane surface of the element, causing flux loss. This often occurs in the first stage of the system, resulting in decreased water production, increased pressure difference in the first stage. Opening the feed water side of the first stage membrane shell will reveal viscous contaminants on the end face of the membrane element.

►Microbiological Fouling

This often occurs in the first stage of the system, resulting in decreased water production, decreased desalination rate, and increased pressure difference in the first stage. Inspection of the feed water side of the first stage membrane shell will reveal viscous contaminants and a fishy smell.

Severe biofouling can cause a significant increase in the pressure drop in the front section of the membrane system, creating high resistance to the feed water flow, easily causing a "telescope" phenomenon at the feed water end of the membrane element and a grid flushing phenomenon at the concentrate end.

►Flocculant/Scale Inhibitor Fouling

When polymeric organic scale inhibitors encounter multivalent cations such as aluminum or residual polymeric cationic flocculants, gel-like precipitates will form, severely fouling the front-stage membrane elements.

This often occurs in the first stage of the system, resulting in decreased water production and increased pressure difference in the first stage. For polyaluminum contamination, the security filter cartridge and membrane end face will show yellowing.

►Inorganic Scale Fouling

Scaling is a water chemistry issue involving the precipitation or deposition of sparingly soluble or insoluble salts, generally occurring in systems without proper pretreatment and with high recovery rates.

Scaling often occurs in the last stage of the system, causing increased pressure difference and decreased water production.

Opening the second stage membrane shell will reveal a large amount of crystalline material deposited on the membrane shell adapter and membrane element.