The desalinization rate is important for measuring the effluent from desalination plants.

The main role of desalination equipment is to remove the salt in seawater, so that the output of fresh water can meet the standards of use, but the desalination rate of reverse osmosis desalination equipment will change after a period of time, and the quality of the water will naturally change.

So, what factors affect the desalination rate of reverse osmosis desalination equipment? The main ones are as follows:

Raw water temperature

Reverse osmosis membrane systems are very sensitive to changes in inlet water temperature. With the increase of water temperature, the water flux increases almost linearly, and the salt transmittance also increases. Therefore, the higher the inlet water temperature, the greater the water production, and at the same time the desalination rate decreases.

Raw water concentration

The salt concentration index of the inlet water will affect the osmotic pressure, which is a function of the concentration and type of salt or organic matter in the water. When the pressure remains constant, the higher the salt content of the inlet water, the lower the flux, increasing the salt flux through the membrane (reducing the desalting rate).

Ion valence number

The desalting rate is increased with the increase of ion valence number, and the desalting rate of bivalent and trivalent salt is higher than that of univalent salt.

PH value

When PH value is low, carbon dioxide in water can enter the production water through the reverse osmosis membrane, and under alkaline or neutral conditions, carbon dioxide in water is converted into bicarbonate ions and carbonate ions, and reverse osmosis has a high removal rate of these two ions, so there is a phenomenon that the removal rate of reverse osmosis membrane increases with the increase of PH value. However, after the PH value is higher than 9.5, the hydroxide ion in the water will increase significantly, and the desalination rate of the reverse osmosis membrane will decrease slightly.

Inlet pressure

The increase of inlet pressure (the effective pressure to overcome osmotic pressure) shows a linear relationship with the increase of water through the membrane. With the increase of inlet pressure, the water flux through the membrane will also increase, and the desalting rate will also increase to a certain extent. When the desalting rate reaches a certain degree, the desalting rate will not change.

recovery

If the recovery rate is increased (the inlet pressure is constant), the salt content remaining in the raw water is higher. Therefore, as the recovery rate increases, the water production will decrease, and the desalination rate will also decrease.

Understand these influencing factors when using, ensure that the changes of these factors are within the normal range, ensure the stable operation of seawater desalination equipment, and better extend the service life of seawater desalination equipment.