Reasons for the Decrease in Ultrapure Water Production

When an ultrapure water system experiences a decrease in water production, it will affect normal water usage. To address this issue, we'll explain why the water production of an ultrapure water system might decrease.

1. Does the operating pressure reach the rated operating pressure of the reverse osmosis membrane?

Determine the rated operating pressure based on the reverse osmosis membrane model. Appropriately increasing the inlet water pressure can increase the water production.

2. Is the reverse osmosis membrane fouled?

Raw water contains a certain concentration of suspended solids and dissolved substances.

Suspended solids mainly consist of inorganic salts, colloids, and biological particles such as microorganisms and algae.

Dissolved substances mainly consist of readily soluble and sparingly soluble salts, metal oxides, acids, and alkalis.

During the reverse osmosis process, the volume of inlet water decreases, while the concentration of suspended particles and dissolved substances increases. Suspended particles will deposit on the membrane, clogging the water flow channels and increasing frictional resistance (pressure drop).

When sparingly soluble salts exceed their saturation limit, they precipitate from the concentrate, forming scale on the membrane surface. This reduces the RO membrane flux, increases operating pressure and pressure drop, and ultimately degrades the quality of the product water.

3. The Influence of Water Temperature

The rated permeate flow rate of a reverse osmosis membrane is designed based on 25℃. For every 1℃ decrease in temperature, the permeate flow rate decreases by 2-3%.

This concludes the explanation of why the permeate flow rate of an ultrapure water system might decrease. We hope this information is helpful and allows for timely resolution of any problems that may arise.